M. Ghodhbane, Davide Beneventi, Abdelkader Zebda et al.

Journal of Power Sources • 2023

Anna Lielpētere, Kavita Jayakumar, Dónal Leech et al.

ACS Sensors • 2023

The lifetime of implantable electrochemical glucose monitoring devices is limited due to the foreign body response and detrimental effects from ascorbic acid (AA) and uric acid (UA) interferents that are components of physiological media. Polymer coatings can be used to shield biosensors from these interferences and prolong their functional lifetime. This work explored several approaches to protect redox polymer-based glucose biosensors against such interferences by designing six targeted multi-layer sensor architectures. Biological interferents, like cells and proteins, and UA and AA interferents were found to have individual effects on the current density and operational stability of glucose biosensors, requiring individual protection and treatment. Protection against biofouling can be achieved using a poly(2-methacryloyloxyethyl phosphorylcholine- co -glycidyl methacrylate) (MPC) zwitterionic polymer coating. An enzyme-scavenging approach was compared to electrostatic repulsion by negatively charged polymers for protection against AA and UA interferences. A multi-layer novel polymer design (PD) system consisting of a cross-linkable negatively charged polyvinylimidazole-polysulfostyrene co-polymer inner layer and a cross-linkable MPC zwitterionic polymer outer layer showed the best protection against AA, UA, and biological interferences. The sensor protected using the novel PD shield displayed the lowest mean absolute relative difference between the glucose reading without the interferent and the reading value with the interferent present and also displayed the lowest variability in sensor readings in complex media. For sensor measurements in artificial plasma, the novel PD extends the linear range ( R 2 = 0.99) of the sensor from 0-10 mM for the control to 0-20 mM, shows a smaller decrease in sensitivity, and retains high current densities. The application of PD multi-target coating improves sensor performance in complex media and shows promise for use in sensors operating in real conditions.

Garima Pandey

SN Applied Sciences • 2019

Adewale George Adeniyi, Sulyman A. Abdulkareem, Comfort Abidemi Adeyanju et al.

Low-carbon Materials and Green Construction • 2023

Abstract Over the years, the devastating impact of climate change has become pronounced due to inadequate regulation for waste disposal in a developing country like Nigeria. The chicken feather-based metal oxide-rich (MOR) biochar was produced using a top-lit updraft reactor at a peak temperature of 417.2 °C to give a yield of 28.19%. The results were analyzed using Brunauer-Emmett-Teller BET, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), and X-ray fluorescence spectroscopy (XRF). The result shows that the sample is mesoporous (pore diameter of 2.132 nm) with a BET surface area of 105.7 m 2 /g. CaO (33.147 wt%) and SO 3 (25.673 wt%) were the major oxides present in notable proportions on the material surface, which were evident in the SEM micrograph. The major elemental compositions of the raw sample were oxygen (36.917 wt%) and calcium (23.690 wt%), and the major minerals present were quartz, marialite, davyne, and graphite. The present study elucidates the successful and efficient material recovery route for the preparation of adsorbents and precursors for many product synthesis processes. Graphical Abstract

Xiayuan Wu, Xiaomin Xiong, Gianluca Brunetti et al.

RSC Advances • 2017

Oxidized MWCNT-modified graphite felt significantly improved Cr( vi ) removal in biocathode MFCs due to its affinity towards microbes and Cr( vi ).

Shmuel Rozenfeld, Lea Ouaknin Hirsch, Bharath Gandu et al.

Energies • 2019

The anode activity in a microbial electrolysis cell (MEC) is known to be a limiting factor in hydrogen production. In this study, the MEC was constructed using different anode materials and a platinum-coated carbon-cloth cathode (CC). The anodes were comprised of CC, stainless steel (SS), and a combination of the two (COMB). The CC and SS anodes were also treated with plasma to improve their surface morphology and hydrophilic properties (CCP and SSP, respectively). A combined version of CCP attached to SS was also applied (COMBP). After construction of the MEC using the different anodes, we conducted electrochemical measurements and examination of biofilm viability. Under an applied voltage of 0.6 V (Ag/AgCl), the currents of a MEC based on CCP and COMBP were 11.66 ± 0.1331 and 16.36 ± 0.3172 A m−2, respectively, which are about three times higher compared to the untreated CC and COMB. A MEC utilizing an untreated SS anode exhibited current of only 0.3712 ± 0.0108 A m−2. The highest biofilm viability of 0.92 OD540 ± 0.07 and hydrogen production rate of 0.0736 ± 0.0022 m3 d−1 m−2 at 0.8 V were obtained in MECs based on the COMBP anode. To our knowledge, this is the first study that evaluated the effect of plasma-treated anodes and the use of a combined anode composed of SS and CC for hydrogen evolution in a MEC.

Muhammad Muddasar, Nicolás Menéndez, Ángela Quero et al.

Advanced Composites and Hybrid Materials • 2024

Abstract The efficient and economical conversion of low-grade waste heat into electricity has promising potential to combat the greenhouse effect and expedite the shift towards sustainable development. This study presents an innovative and appealing approach through the utilization of lignin, an abundant waste product derived from the paper and pulp industry, to develop hydrogels as compelling and sustainable materials for application in ionic thermoelectricity. Various compositions were evaluated to examine the impacts of varying lignin concentrations, types of electrolytes, concentrations of crosslinkers, and electrolyte concentrations on the ionic thermoelectric performance of the hydrogels. The optimized lignin-derived hydrogel, infiltrated with a 6 M KOH electrolyte, demonstrates high ionic conductivity (226.5 mS/cm) and a superior Seebeck coefficient of 13 mV/K. This results in a remarkable power factor (3831 µW/m·K 2 ) that leads to an impressive Figure of merit (ZT i ) (3.75), surpassing most of the existing state-of-the-art materials and making it the most efficient sustainable ionic thermoelectric material reported until now. These findings underscore the exceptional performance of lignin-based hydrogels in the realm of low-grade waste energy harvesting applications. The present study contributes to address the challenges posed by waste heat through effectively harnessing low-grade waste heat through the utilization of sustainable lignin-based hydrogels while reducing the reliance on fossil fuels and minimizing greenhouse gas emissions. Graphical Abstract

Rubin Gulaboski, Valentin Mirčeski

Macedonian Journal of Chemistry and Chemical Engineering • 2020

Protein-film voltammetry (PFV) is considered the simplest methodology to study the electrochemistry of lipophilic redox enzymes in an aqueous environment. By anchoring particular redox enzymes on the working electrode surface, it is possible to get an insight into the mechanism of enzyme action. The PFV methodology enables access to the relevant thermodynamic and kinetic parameters of the enzyme-electrode reaction and enzyme-substrate interactions, which is important to better understand many metabolic pathways in living systems and to delineate the physiological role of enzymes. PFV additionally provides important information which is useful for designing specific biosensors, simple medical devices and bio-fuel cells. In the current review, we focus on some recent achievements of PFV, while presenting some novel protocols that contribute to a better communication between redox enzymes and the working electrode. Insights to several new theoretical models that provide a simple strategy for studying electrode reactions of immobilized enzymes and that enable both kinetic and thermodynamic characterization of enzyme-substrate interactions are also provided. In addition, we give a short overview to several novel voltammetric techniques, derived from the perspective of square-wave voltammetry, which seem to be promising tools for application in PFV.

Zhou Jian, Chang Liu, Hao Yu et al.

Applied Sciences • 2023

Enzymatic biofuel cells (EBFCs) are devices that use natural enzymes as catalysts to convert chemical energy from bio-sourced fuels into electrical energy. In this review, we summarize recent research progress and applications in the field of biofuel cells based on immobilized enzymes. Specifically, we discuss how to optimize and improve the electrochemical performance and operational stability of enzymatic biofuel cells through enzyme immobilization materials, enzyme immobilization methods, electron transfer improvement on enzyme electrodes, and cell construction methods. We also cover current and future practical applications of biofuel cells based on immobilized enzymes, including implantable enzymatic biofuel cells and wearable enzymatic biofuel cells. Additionally, we present some of the issues that still need to be addressed in the field of biofuel cells based on immobilized enzymes to ensure their technical and commercial viability and sustainability.

Li Jiang, Deqiang Yin, Yi Qin

Manufacturing Review • 2023

As one of the most versatile elements, carbon materials occupy the most plentiful allotropies composed of pure or mixed hybridization orbitals of sp 1 /sp 2 /sp 3 . The design and synthesis of new carbon materials may be stimulated based on a deeper understanding of underlying structures and related properties. In this review, the initial early discoveries of carbon materials are examined based on their hybridization of orbitals. According to the type of hybridization, the discovered carbon materials are firstly classified and introduced in detail based on their crystal structures. Secondly, its physical and chemical properties, mainly including mechanical properties, optical properties and electronic properties, are reviewed. Thirdly, the existing methods of predicting carbon structure and synthesizing carbon materials are classified and summarized, and some typical carbon materials predicted or prepared are discussed respectively. Then, the main applications of newly synthesized carbon materials in the last two decades are classified and summarized, and the microstructure is linked with the macro properties and specific applications. Finally, the future research opportunities for carbon materials and their potential applications are prospected from the aspects of the gap between theoretical prediction and preparation, the current research hotspot of carbon materials and the incomplete application of carbon materials. It is the authors' intention for this review paper to serve not only as a valuable reference for research into carbon materials and related composites, but also as a guidance for novel materials design at the atomic level.

Navid Rabiee, Mojtaba Bagherzadeh, Amir Mohammad Ghadiri et al.

Journal of nanostructure in chemistry • 2021

Andressa R. Pereira, João de Souza, Andressa Gonçalves et al.

Journal of the Brazilian Chemical Society • 2017

Hierarchical 3-dimensional flexible carbon fiber (FCF) array is a candidate as flexible electrode for enzyme electrochemistry, with interesting properties for application in enzymatic biofuel cell and implantable biosensors. Here, we show the fabrication of oxidized FCF electrode (FCFO) based on chemical surface treatment, a wet oxidation method by using permanganate ions. Compared with pristine FCF, FCFO is rougher; the scratches become wider and deeper, with some defects in the basal planes and some cracked structures. X-ray photoelectron spectroscopy data suggests a correlation between the carbon structures and the appearance of chemical groups containing oxygen atoms. Finally, we show how the bioelectrocatalysis of ethanol by using FCFO arrays modified with NAD-dependent alcohol dehydrogenase (ADH) is positively influenced by the fibers treatment oxidation process.

Sangam Srikanth, Sohan Dudala, U S Jayapiriya et al.

Scientific Reports • 2021

Controlled, stable and uniform temperature environment with quick response are crucial needs for many lab-on-chip (LOC) applications requiring thermal management. Laser Induced Graphene (LIG) heater is one such mechanism capable of maintaining a wide range of steady state temperature. LIG heaters are thin, flexible, and inexpensive and can be fabricated easily in different geometric configurations. In this perspective, herein, the electro-thermal performance of the LIG heater has been examined for different laser power values and scanning speeds. The experimented laser ablated patterns exhibited varying electrical conductivity corresponding to different combinations of power and speed of the laser. The conductivity of the pattern can be tailored by tuning the parameters which exhibit, a wide range of temperatures making them suitable for diverse lab-on-chip applications. A maximum temperature of 589 °C was observed for a combination of 15% laser power and 5.5% scanning speed. A LOC platform was realized by integrating the developed LIG heaters with a droplet-based microfluidic device. The performance of this LOC platform was analyzed for effective use of LIG heaters to synthesize Gold nanoparticles (GNP). Finally, the functionality of the synthesized GNPs was validated by utilizing them as catalyst in enzymatic glucose biofuel cell and in electrochemical applications.

Aya A. Najim, Ahmed Y. Radeef, Ibrahim al‐Doori et al.

Journal of Chemical Technology & Biotechnology • 2024

Abstract Biodegradation of pollutants is one of the most economical methods for their removal and usually is accompanied by no production of toxic by‐products. In general, this approach is favored over others because it offers reduced expenses and the potential for complete mineralization. In order to enhance the viability and longevity of the bioremediation agents within polluted areas, it becomes necessary to immobilize the cells. Cell immobilization refers to the procedure of confining intact cells to specific areas within a device or material, without compromising their essential biological functions. A wide variety of carriers and approaches have been used for the restriction of various cells. Immobilization techniques, such as microencapsulation, have opened up new possibilities in biotechnology by facilitating the development of artificial organs, cell therapies and drug delivery systems. Researchers have found promising outcomes in various applications through the immobilization of microorganisms. This approach enhances stability, reusability and catalytic efficiency, making immobilization a valuable strategy for biocatalysis, bioremediation and other biotechnological processes. Notably, the use of immobilized microorganisms has led to significant improvements in the removal of pollutants, with some studies achieving 100% efficiency. When comparing the degradation of pollutants between free and immobilized microorganisms over the same time period, the results demonstrated that immobilized microorganisms achieved a removal efficiency >21% more than that of free microbial consortia. The primary objective of this review is to give an overview of the key scientific aspects related to bioremediation of various pollutants using immobilized cells, with a particular focus on the techniques used to entrap the cells. © 2024 Society of Chemical Industry (SCI).

Marcelinus Christwardana, Yongjin Chung, Yongchai Kwon

NPG Asia Materials • 2017

A new enzyme catalyst consisting of pyrenecarboxaldehyde (PCA) and glucose oxidase (GOx) immobilized on polyethyleneimine (PEI) and a carbon nanotube supporter (CNT/PEI/[PCA/GOx]) is suggested, and the performance and stability of an enzymatic biofuel cell (EBC) using the new catalyst are evaluated. Using PCA, the amount of immobilized GOx increases (3.3 U mg−1) and the electron transfer rate constant of the CNT/PEI/[PCA/GOx] is promoted (11.51 s−1). Also, the catalyst induces excellent EBC performance (maximum power density (MPD) of 2.1 mW cm−2), long-lasting stability (maintenance of 93% of the initial MPD after 4 weeks) and superior catalytic activity (flavin adenine dinucleotide redox reaction rate of 0.62 mA cm−2 and Michaelis–Menten constant of 0.99 mM). These characteristics are ascribed to effects of (i) electron collection due to hydrophobic interactions, (ii) electron transfer pathways due to π-conjugated bonds and (iii) enzyme stabilization due to π-hydrogen bonds that are newly induced by the PCA/GOx composite. The existence of such positive interactions is properly verified using X-ray photoelectron spectroscopy and enzyme activity measurements. Fuel cells that power medical implants using body-friendly materials stand to benefit from a new catalyst with extra-tight enzyme grip. Glucose oxidase is protein complex that catalytically oxidizes various substrates, including glucose, glycerol and water, and neutral pH. Prof. Yongchai Kwon from Seoul National University of Science and Technology and co-workers now report that modifying outer perimeter of glucose oxidase with allotropes of carbon with a cylindrical nanostructure improves its use in enzymatic biofuel cells. The additional polycyclic aromatic hydrocarbon consisting of four fused benzene rings, called pyrenecarboxaldehydes, enabled strong immobilization of the protein onto a conductive support containing similarly shaped carbon nanotubes. The team identified three new bonding interactions between the biocatalyst and the support that improved electron flow and boosted enzyme stabilization, factors that enhanced the power output and longevity of prototype biofuel cells. New enzyme catalyst consisting of pyrenecarboxaldehyde (PCA) and glucose oxidase (GOx) immobilized on polyethyleneimine and carbon nanotube (CNT/PEI/[PCA/GOx]) is developed with performance and stability evaluations of enzymatic biofuel cell (EBC) using the new catalyst. By employment of PCA, the amount of immobilized GOx increases and electron transfer of CNT/PEI/[PCA/GOx] is facilitated. With that, superior EBC performance, long-lasting stability and excellent catalytic activities are gained. Such results are attributed to effects of (i) electron collection by hydrophobic interactions, (ii) electron transfer by π-conjugated bonds and (iii) enzyme stabilization by π-hydrogen bonds. Validity of such three positive effects is proved by various measurements.

Natcha Rasitanon, Kornautchaya Veenuttranon, Hnin Thandar Lwin et al.

International Journal of Molecular Sciences • 2023

Glucose oxidase (GOx)-based electrodes are important for bioelectronics, such as glucose sensors. It is challenging to effectively link GOx with nanomaterial-modified electrodes while preserving enzyme activity in a biocompatible environment. To date, no reports have used biocompatible food-based materials, such as egg white proteins, combined with GOx, redox molecules, and nanoparticles to create the biorecognition layer for biosensors and biofuel cells. This article demonstrates the interface of GOx integrated with egg white proteins on a 5 nm gold nanoparticle (AuNP) functionalized with a 1,4-naphthoquinone (NQ) and conjugated with a screen-printed flexible conductive carbon nanotube (CNT)-modified electrode. Egg white proteins containing ovalbumin can form three-dimensional scaffolds to accommodate immobilized enzymes and adjust the analytical performance. The structure of this biointerface prevents the escape of enzymes and provides a suitable microenvironment for the effective reaction. The bioelectrode's performance and kinetics were evaluated. Using redox-mediated molecules with the AuNPs and the three-dimensional matrix made of egg white proteins improves the transfer of electrons between the electrode and the redox center. By engineering the layer of egg white proteins on the GOx-NQ-AuNPs-mediated CNT-functionalized electrodes, we can modulate analytical performances such as sensitivity and linear range. The bioelectrodes demonstrate high sensitivity and can prolong the stability by more than 85% after 6 h of continuous operation. The use of food-based proteins with redox molecule-modified AuNPs and printed electrodes demonstrates advantages for biosensors and energy devices due to their small size, large surface area, and ease of modification. This concept holds a promise for creating biocompatible electrodes for biosensors and self-sustaining energy devices.

Emma Roubaud, Rémy Lacroix, Serge Da Silva et al.

Frontiers in Energy Research • 2019

Anode material selection is crucial when it comes to building up-scaled microbial electrolysis cells (MEC), as it as a huge influence on the achievable current density and account for a large part of the MEC total investment cost. Graphite is a material that is perfectly suited to the creation of up-scaled bioanodes as it is conductive, chemically stable, biocompatible and relatively cheap but there are a very large number of commercially available grades of industrial graphite. . In this study, five grades of industrial synthetic graphite (named G1 to G5) were bench tested to select the most suitable grade for future development of 3D bioanode for domestic wastewater (dWW) fed MEC application. The five grades of graphite have been selected with similar physico-chemical and surface properties (electrical resistivity, surface roughness and hydrophobicity) theoretically appropriate for EA biofilm development. Nevertheless, significant current density disparities where observed with the five graphite grades, which can certainly be explained by the fabrication procedures of the respective material grades. With the graphite grade giving the most efficient anodes (G3), an average steady state current density of 2.3 A/m² was produced, outperforming the other grades by at least 15%. Even though all graphites had very close physico-chemical characteristics, the grade had a clear significant influence on the current densities produced. G3 graphite was finally compared to carbon felt (CF) and carbon cloth (CC) both in terms of bio-electrochemical current production and bacterial communities colonizing electrodes. G3 bioanodes outperformed CF and CC bioanodes by 50% in term of steady state current density. Biofilms microbial population analysis showed that the Geobacter species was present at 82% on G3 bioanodes, 39% on CF bioanodes and 61% on CC bioanodes when it was only present at 0.06% in the activated sludge used as inoculum. This significant difference in bacterial enrichment could come from the huge gap between materials resistivity, as graphite resistivity is 200-fold lower than CF and CC resistivities. The strongly hydrophilic surface of G3 graphite was also certainly beneficial for biofilm development compared to the hydrophobic surfaces of CF and CC.

Kou Yang, Konstantin G. Nikolaev, Xiaolai Li et al.

Proceedings of the National Academy of Sciences • 2024

The extraction of gold (Au) from electronic waste (e-waste) has both environmental impact and inherent value. Improper e-waste disposal poses environmental and health risks, entailing substantial remediation and healthcare costs. Large efforts are applied for the recovery of Au from e-waste using complex processes which include the dissolution of Au, its adsorption in an ionic state and succeeding reduction to metallic Au. These processes themselves being complex and utilizing harsh chemicals contribute to the environmental impact of e-waste. Here, we present an approach for the simultaneous recovery and reduction of Au 3+ and Au + ions from e-waste to produce solid Au 0 forms, thus skipping several technological steps. We develop a nanoscale cross-dimensional composite material via self-assembly of two-dimensional graphene oxide and one-dimensional chitosan macromolecules, capable of acting simultaneously as a scavenger of gold ions and as a reducing agent. Such multidimensional architecture doesn't require to apply any voltage for Au adsorption and reduction and solely relies on the chemisorption kinetics of Au ions in the heterogeneous GO/CS nanoconfinements and their chemical reduction on multiple binding sites. The cooperative phenomena in ionic absorption are responsible for the extremely high efficiency of gold extraction. The extraction capacity reaches 16.8 g/g for Au 3+ and 6.2 g/g for Au + , which is ten times larger than any existing gold adsorbents can propose. The efficiency is above 99.5 wt.% (current limit is 75 wt.%) and extraction ability is down to very low concentrations of 3 ppm.

Jiameng Li, Jiayin Liu, Ziyue Wu et al.

Science Advances • 2023

Real-time glucose monitoring conventionally involves non-bioresorbable semi-implantable glucose sensors, causing infection and pain during removal. Despite bioresorbable electronics serves as excellent alternatives, the bioresorbable sensor dissolves in aqueous environments with interferential biomolecules. Here, the theories to achieve stable electrode potential and accurate electrochemical detection using bioresorbable materials have been proposed, resulting in a fully printed bioresorbable electrochemical device. The adverse effect caused by material degradation has been overcome by a molybdenum-tungsten reference electrode that offers stable potential through galvanic-coupling and self-compensation modules. In vitro and in vivo glucose monitoring has been conducted for 7 and 5 days, respectively, followed by full degradation within 2 months. The device offers a glucose detection range of 0 to 25 millimolars and a sensitivity of 0.2458 microamperes per millimolar with anti-interference capability and biocompatibility, indicating the possibility of mass manufacturing high-performance bioresorbable electrochemical devices using printing and low-temperature water-sintering techniques. The mechanisms may be implemented developing more comprehensive bioresorbable sensors for chronic diseases.

Chongyang Hou, Shuye Zhang, Rui Liu et al.

InfoMat • 2024

Abstract Flexible electronics has emerged as a continuously growing field of study. Two‐dimensional (2D) materials often act as conductors and electrodes in electronic devices, holding significant promise in the design of high‐performance, flexible electronics. Numerous studies have focused on harnessing the potential of these materials for the development of such devices. However, to date, the incorporation of 2D materials in flexible electronics has rarely been summarized or reviewed. Consequently, there is an urgent need to develop comprehensive reviews for rapid updates on this evolving landscape. This review covers progress in complex material architectures based on 2D materials, including interfaces, heterostructures, and 2D/polymer composites. Additionally, it explores flexible and wearable energy storage and conversion, display and touch technologies, and biomedical applications, together with integrated design solutions. Although the pursuit of high‐performance and high‐sensitivity instruments remains a primary objective, the integrated design of flexible electronics with 2D materials also warrants consideration. By combining multiple functionalities into a singular device, augmented by machine learning and algorithms, we can potentially surpass the performance of existing wearable technologies. Finally, we briefly discuss the future trajectory of this burgeoning field. This review discusses the recent advancements in flexible sensors made from 2D materials and their applications in integrated architecture and device design.

Sergei Tarasov, Yulia Plekhanova, Vadim Kashin et al.

Biosensors • 2022

Microbial fuel cells (MFCs) are a variety of bioelectrocatalytic devices that utilize the metabolism of microorganisms to generate electric energy from organic matter. This study investigates the possibility of using a novel PEDOT:PSS/graphene/Nafion composite in combination with acetic acid bacteria Gluconobacter oxydans to create a pure culture MFC capable of effective municipal wastewater treatment. The developed MFC was shown to maintain its activity for at least three weeks. The level of COD in municipal wastewater treatment was reduced by 32%; the generated power was up to 81 mW/m 2 with a Coulomb efficiency of 40%. Combining the MFC with a DC/DC boost converter increased the voltage generated by two series-connected MFCs from 0.55 mV to 3.2 V. A maximum efficiency was achieved on day 8 of MFC operation and was maintained for a week; capacitors of 6800 µF capacity were fully charged in ~7 min. Thus, G. oxydans cells can become an important part of microbial consortia in MFCs used for treatment of wastewaters with reduced pH.

Fereshte Gholami, Aso Navaee, Abdollah Salimi et al.

Scientific Reports • 2018

Bipolar electrochemistry (BPE) has been lately explored as a simple, reliable and novel electrochemical technique for the adjustment of various conductive substrates. Herein, BPE is performed to derive both of cathode and anode electrodes for the development of mediatorless/membraneless biofuel cell (BFC). On one hand, a preferable substrate for immobilization of bilirubin oxidase enzyme is prepared based on the electropolymerization of thiophene-3-carboxcylic acid (TCA) on an Au microfilm as a bipolar electrode. The resulted biocathode as novel bioelectrocatalyst offers a high electrocatalytic activity toward direct oxygen reduction reaction (ORR) with onset potential and current density of 0.55 V (vs. Ag/AgCl) and 867 μA cm -2 , respectively. On the other hand, another analogous Au bipolar electrode is electroplated through BPE to derive Au nanostructures (AuNSs). This modified Au electrode is utilized as an anodic platform for immobilization of flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) enzyme aimed at electrocatalytic glucose oxidation. The prepared bioanode displays a current density of 2.7 mA cm -2 with onset potential of -0.03 V. Finally, the proposed bioanode and biocacthode in an assembled membraneless glucose/O 2 BFC offers a power output of 146 μW cm -2 with open circuit voltage of 0.54 V. This novel BPE method provides disposable electrochemical platforms for design of novel sensors, biosensors or other devices.

Anuja Bokare, Sowbaranigha Chinnusamy, Folarin Erogbogbo

Catalysts • 2021

The focus of current research in material science has shifted from “less efficient” single-component nanomaterials to the superior-performance, next-generation, multifunctional nanocomposites. TiO2 is a widely used benchmark photocatalyst with unique physicochemical properties. However, the large bandgap and massive recombination of photogenerated charge carriers limit its overall photocatalytic efficiency. When TiO2 nanoparticles are modified with graphene quantum dots (GQDs), some significant improvements can be achieved in terms of (i) broadening the light absorption wavelengths, (ii) design of active reaction sites, and (iii) control of the electron-hole (e−-h+) recombination. Accordingly, TiO2-GQDs nanocomposites exhibit promising multifunctionalities in a wide range of fields including, but not limited to, energy, biomedical aids, electronics, and flexible wearable sensors. This review presents some important aspects of TiO2-GQDs nanocomposites as photocatalysts in energy and biomedical applications. These include: (1) structural formulations and synthesis methods of TiO2-GQDs nanocomposites; (2) discourse about the mechanism behind the overall higher photoactivities of these nanocomposites; (3) various characterization techniques which can be used to judge the photocatalytic performance of these nanocomposites, and (4) the application of these nanocomposites in biomedical and energy conversion devices. Although some objectives have been achieved, new challenges still exist and hinder the widespread application of these nanocomposites. These challenges are briefly discussed in the Future Scope section of this review.

Bekir Çakıroğlu, Naiba Jabiyeva, Michael Holzinger

Biosensors and Bioelectronics • 2023

Qiang Cai, Fei Shen, Jianqing Zhao et al.

iScience • 2024

Self-sustained smart textiles require a miniaturized and flexible power source, while the state-of-the-art lithium-ion battery cannot be seamlessly integrated into smart textiles. Enzymatic biofuel cells (EBFC), utilizing physiological glucose or lactate as fuels to convert chemical energy into electricity, are a potential alternative power source. In comparison to other proposed energy harvesters relying on solar and biomechanical energy, EBFCs feature several key properties, including continuous power generation, biocompatible interfaces without using toxic elements, simple configuration without extra packaging, and biodegradability. There is an urgent need to introduce EBFCs to the researchers working on smart textiles, who typically are not expert on bioelectrochemistry. This minireview first introduces the working principle of EBFC and then summarizes its recent progress on fibers, yarns, and textiles. It's expected that this review can help to bridge the knowledge gap and provide the community of smart textiles with information on both the strengths and limitations of EBFCs.

Paolo Bollella, Yuya Hibino, Paolo Conejo-Valverde et al.

Analytical and Bioanalytical Chemistry • 2019

Graphite electrodes were modified with triangular (AuNTrs) or spherical (AuNPs) nanoparticles and further modified with fructose dehydrogenase (FDH). The present study reports the effect of the shape of these nanoparticles (NPs) on the catalytic current of immobilized FDH pointing out the different contributions on the mass transfer-limited and kinetically limited currents. The influence of the shape of the NPs on the mass transfer-limited and the kinetically limited current has been proved by using two different methods: a rotating disk electrode (RDE) and an electrode mounted in a wall jet flow-through electrochemical cell attached to a flow system. The advantages of using the wall jet flow system compared with the RDE system for kinetic investigations are as follows: no need to account for substrate consumption, especially in the case of desorption of enzyme, and studies of product-inhibited enzymes. The comparison reveals that virtually identical results can be obtained using either of the two techniques. The heterogeneous electron transfer (ET) rate constants (k S ) were found to be 3.8 ± 0.3 s -1 and 0.9 ± 0.1 s -1 , for triangular and spherical NPs, respectively. The improvement observed for the electrode modified with AuNTrs suggests a more effective enzyme-NP interaction, which can allocate a higher number of enzyme molecules on the electrode surface. Graphical abstract The shape of gold nanoparticles has a crucial effect on the catalytic current related to the oxidation of D-(-)-fructose to 5-keto-D-(-)-fructose occurring at the FDH-modified electrode surface. In particular, AuNTrs have a higher effect compared with the spherical one.

Jingshuai Guo, Amir Ehsan Niaraki Asli, Kelli R. Williams et al.

Biosensors • 2019

Parkinson's disease (PD) is the second most common neurodegenerative disease in the United States after Alzheimer's disease (AD). To help understand the electrophysiology of these diseases, N27 neuronal cells have been used as an in vitro model. In this study, a flexible graphene-based biosensor design is presented. Biocompatible graphene was manufactured using a liquid-phase exfoliation method and bovine serum albumin (BSA) for further exfoliation. Raman spectroscopy results indicated that the graphene produced was indeed few-layer graphene (FLG) with ID/IGGraphene= 0.11. Inkjet printing of this few-layer graphene ink onto Kapton polyimide (PI) followed by characterization via scanning electron microscopy (SEM) showed an average width of ≈868 µm with a normal thickness of ≈5.20 µm. Neuronal cells were placed on a thermally annealed 3D printed graphene chip. A live-dead cell assay was performed to prove the biosensor biocompatibility. A cell viability of approximately 80% was observed over 96 h, which indicates that annealed graphene on Kapton PI substrate could be used as a neuronal cell biosensor. This research will help us move forward with the study of N27 cell electrophysiology and electrical signaling.

Qiang Zhang, Soham Das, Liang Zheng et al.

Med-X • 2025

Abstract The development of wearable energy sto rage and harvesting devices is pivotal for advancing next-generation healthcare technologies, facilitating continuous and real-time health monitoring. Traditional wearable devices have been constricted by bulky and rigid batteries, limiting their practicality and comfort. However, recent advancements in materials science have enabled the creation of flexible, stretchable, and lightweight energy storage and harvesting solutions. The integration of energy storage and harvesting technologies is essential for developing self-sustaining systems that minimize reliance on external power sources and enhance device longevity. These integrated systems ensure the continuous operation of sensors and processors vital for real-time health monitoring. This review examines recent significant progress in wearable energy storage and harvesting, focusing on the latest advancements in wearable devices, solar cells, biofuel cells, triboelectric nanogenerators, magnetoelastic gene rators, supercapacitors, lithium-ion batteries, and zinc-ion batteries. It also discusses key parameters crucial for their wearable applications, such as energy density, power density, and durability. Finally, the review addresses future challenges and prospects in this rapidly evolving field, underscoring the potential for developing innovative, self-powered wearable systems for healthcare applications. Graphical Abstract

Shoujie Guan, Jingxi Wang, Yang Yang et al.

Advanced Functional Materials • 2023

Abstract With the emerging demand of implantable microelectronics, it essentially requires the fully integrated and reliable power supplies. The study reports a stretchable and flexible electrospinning‐based glucose/O 2 biofuel cell with glucose oxidase bioanode, Pt/C cathode and thermoplastic polyurethane substrate, which is capable for adapting to the various stresses and strains caused by individual movement. The rigid benzene rings and elastic chain segments of thermoplastic polyurethane ensure its superior tensile property. Furthermore, the stable covalent connections between the activated carbon nanotubes (CNTs‐COOH) and glucose oxidase inside 3D thermoplastic polyurethane network are established by amide reaction to ensure the rapid direct electron transfer of bioanode and stable power output of device in flexible environments. The biofuel cell exhibits an open circuit voltage of 0.575 V, and high‐power density of 57 µW cm −2 in 5 mM glucose. Moreover, the power‐generation properties of implantable biofuel cell keep steady, and its power density exhibits limited fluctuations on the dorsum of rat when bending, stretching, and twisting in 28 days. There is no obvious local inflammation or systemic abnormalities in rats. It satisfies the impressive biocompatible requirement, demonstrating the promising potential of electrospinning‐based biofuel cell as a robust self‐sustained power source for implantable electronics.

Andrés Felipe Quintero-Jaime, Javier Quílez‐Bermejo, Diego Cazorla‐Amorós et al.

Electrochimica Acta • 2020

Anjitha Thadathil, Hareesh Pradeep, Deepak Joshy et al.

Materials Advances • 2022

This review focuses on the synthesis and improvement of two types of N-containing conducting polymers – polypyrrole and polyindole – as well as an in-depth analysis of their binary and ternary nanocomposites in the treatment of contaminants, sensing, and green chemistry.

Asta Kausaite‐Minkstimiene, Algimantas Kaminskas, Anton Popov et al.

Scientific Reports • 2021

In this study, we reported the development of Prussian blue (PB), poly(pyrrole-2-carboxylic acid) (PPCA), and glucose oxidase (GOx) biocomposite modified graphite rod (GR) electrode as a potential biocathode for single enzyme biofuel cell fuelled by glucose. In order to design the biocathode, the GR electrode was coated with a composite of PB particles embedded in the PPCA shell and an additional layer of PPCA by cyclic voltammetry. Meanwhile, GOx molecules were covalently attached to the carboxyl groups of PPCA by an amide bond. The optimal conditions for the biocathode preparation were elaborated experimentally. After optimization, the developed biocathode showed excellent electrocatalytic activity toward the reduction of H 2 O 2 formed during GOx catalyzed glucose oxidation at a low potential of 0.1 V vs Ag/AgCl, as well as good electrochemical performance. An electrocatalytic current density of 31.68 ± 2.70 μA/cm 2 and open-circuit potential (OCP) of 293.34 ± 15.70 mV in O 2 -saturated 10 mM glucose solution at pH 6.0 were recorded. A maximal OCP of 430.15 ± 15.10 mV was recorded at 98.86 mM of glucose. In addition, the biocathode showed good operational stability, maintaining 95.53 ± 0.15% of the initial response after 14 days. These results suggest that this simply designed biocathode can be applied to the construction of a glucose-powered single enzyme biofuel cell.

Andrew Yun Ru Ng, Bhanupriya Boruah, Kek Foo Chin et al.

ChemNanoMat • 2019

Abstract Photoelectrochemical cells have been used as one of the most common artificial photosynthetic approaches to mimic natural photosynthetic water splitting reactions. However, despite the tremendous advances made to improve the affordability and efficiency of photoelectrochemical water splitting, it is still not an economically feasible method to produce solar fuels currently since only the H 2 evolving reduction half‐reaction generates valuable fuels. Therefore, in this review, we intend to highlight other underexplored substrates and reactions for producing solar fuels in photoelectrochemical cells, as well as alternative architectures including temporally independent and biohybrid systems. We show that besides water oxidation, electrocatalytic or photoredox reactions for pollutant degradation, biomass valorization, and organic chemical synthesis can be or have been successfully adapted for photoelectrochemical cells, thus offering a virtually infinite number of possibilities for artificial photosynthetic applications which generate valuable products in both the reduction and oxidation half reactions.

Keith J. Stine

Applied Sciences • 2019

The development of biosensors for a range of analytes from small molecules to proteins to oligonucleotides is an intensely active field. Detection methods based on electrochemistry or on localized surface plasmon responses have advanced through using nanostructured electrodes prepared by electrodeposition, which is capable of preparing a wide range of different structures. Supported nanoparticles can be prepared by electrodeposition through applying fixed potentials, cycling potentials, and fixed current methods. Nanoparticle sizes, shapes, and surface densities can be controlled, and regular structures can be prepared by electrodeposition through templates. The incorporation of multiple nanomaterials into composite films can take advantage of the superior and potentially synergistic properties of each component. Nanostructured electrodes can provide supports for enzymes, antibodies, or oligonucleotides for creating sensors against many targets in areas such as genomic analysis, the detection of protein antigens, or the detection of small molecule metabolites. Detection can also be performed using electrochemical methods, and the nanostructured electrodes can greatly enhance electrochemical responses by carefully designed schemes. Biosensors based on electrodeposited nanostructures can contribute to the advancement of many goals in bioanalytical and clinical chemistry.

Huawei Jiang, Md. Azahar Ali, Zhen Xu et al.

Scientific Reports • 2017

This paper reports on a miniaturized microbial fuel cell with a microfluidic flow-through configuration: a porous anolyte chamber is formed by filling a microfluidic chamber with three-dimensional graphene foam as anode, allowing nutritional medium to flow through the chamber to intimately interact with the colonized microbes on the scaffolds of the anode. No nutritional media flow over the anode. This allows sustaining high levels of nutrient utilization, minimizing consumption of nutritional substrates, and reducing response time of electricity generation owing to fast mass transport through pressure-driven flow and rapid diffusion of nutrients within the anode. The device provides a volume power density of 745 μW/cm 3 and a surface power density of 89.4 μW/cm 2 using Shewanella oneidensis as a model biocatalyst without any optimization of bacterial culture. The medium consumption and the response time of the flow-through device are reduced by 16.4 times and 4.2 times, respectively, compared to the non-flow-through counterpart with its freeway space volume six times the volume of graphene foam anode. The graphene foam enabled microfluidic flow-through approach will allow efficient microbial conversion of carbon-containing bioconvertible substrates to electricity with smaller space, less medium consumption, and shorter start-up time.

Raja Saad Alruwais, Waheed A. Adeosun, Hadi M. Marwani et al.

Polymers • 2021

Lead is a potentially toxic element (PTE) that has several adverse medical effects in humans. Its presence in the environment became prominent due to anthropogenic activities. The current study explores the use of newly developed composite materials (organic-inorganic hybrid) based on PANI-GO-APTES for electrochemical detection of Pb 2+ in aqueous solution. The composite material (PANI-GO-APTES) was synthesized by chemical method and was characterized with SEM, XPS, XEDS, XRD, TGA, FTIR, EIS and CV. The result of characterization indicates the successful synthesis of the intended material. The PANI-GO-APTES was successfully applied for electrochemical detection of Pb 2+ using cyclic voltammetry and linear sweep voltammetry method. The limit of detection of Pb 2+ was 0.0053 µM in the linear range of 0.01 µM to 0.4 µM. The current response produced during the electrochemical reduction of Pb 2+ catalyzed by PANI-GO-APTES was also very repeatable, reproducible and rapid. The application of PANI-GO-APTES-modified GCE in real sample analysis was also established. Therefore, PANI-GO-APTES is presented as a potential Pb 2+ sensor for environmental and human health safety.

Natalija German, Almira Ramanavičienė, Arūnas Ramanavičius

Polymers • 2020

Nanocomposites based on two conducting polymers, polyaniline (PANI) and polypyrrole (Ppy), with embedded glucose oxidase (GOx) and 6 nm size gold nanoparticles (AuNPs (6nm) ) or gold-nanoclusters formed from chloroaurate ions (AuCl 4 - ), were synthesized by enzyme-assisted polymerization. Charge (electron) transfer in systems based on PANI/AuNPs (6nm) -GOx, PANI/AuNPs (AuCl4 - ) -GOx, Ppy/AuNPs (6nm) -GOx and Ppy/AuNPs (AuCl4 - ) -GOx nanocomposites was investigated. Cyclic voltammetry (CV)-based investigations showed that the reported polymer nanocomposites are able to facilitate electron transfer from enzyme to the graphite rod (GR) electrode. Significantly higher anodic current and well-defined red-ox peaks were observed at a scan rate of 0.10 V s -1 . Logarithmic function of anodic current (log I pa ), which was determined by CV-based experiments performed with glucose, was proportional to the logarithmic function of a scan rate (log v ) in the range of 0.699-2.48 mV s -1 , and it indicates that diffusion-controlled electrochemical processes were limiting the kinetics of the analytical signal. The most efficient nanocomposite structure for the design of the reported glucose biosensor was based on two-day formed Ppy/AuNPs (AuCl4 - ) -GOx nanocomposites. GR/Ppy/AuNPs (AuCl4 - ) -GOx was characterized by the linear dependence of the analytical signal on glucose concentration in the range from 0.1 to 0.70 mmol L -1 , the sensitivity of 4.31 mA mM cm -2 , the limit of detection of 0.10 mmol L -1 and the half-life period of 19 days.

Zepeng Kang, Kailong Jiao, Chao Yu et al.

RSC Advances • 2017

Due to their unique physicochemical properties, carbon nanochips (CNCs) have been used for studies of the direct electrochemical and electrocatalytic properties of oxidoreductase.

Yufei Yang, Yuanqiang Hao, Lijie Huang et al.

Molecules • 2024

Formaldehyde, a ubiquitous indoor air pollutant, plays a significant role in various biological processes, posing both environmental and health challenges. This comprehensive review delves into the latest advancements in electrochemical methods for detecting formaldehyde, a compound of growing concern due to its widespread use and potential health hazards. This review underscores the inherent advantages of electrochemical techniques, such as high sensitivity, selectivity, and capability for real-time analysis, making them highly effective for formaldehyde monitoring. We explore the fundamental principles, mechanisms, and diverse methodologies employed in electrochemical formaldehyde detection, highlighting the role of innovative sensing materials and electrodes. Special attention is given to recent developments in nanotechnology and sensor design, which significantly enhance the sensitivity and selectivity of these detection systems. Moreover, this review identifies current challenges and discusses future research directions. Our aim is to encourage ongoing research and innovation in this field, ultimately leading to the development of advanced, practical solutions for formaldehyde detection in various environmental and biological contexts.

Lili Cao, Juan Chen, Jingyu Pang et al.

Molecules • 2024

Enzyme biofuel cells (EBFCs) can convert chemical or biochemical energy in fuel into electrical energy, and therefore have received widespread attention. EBFCs have advantages that traditional fuel cells cannot match, such as a wide range of fuel sources, environmental friendliness, and mild reaction conditions. At present, research on EBFCs mainly focuses on two aspects: one is the use of nanomaterials with excellent properties to construct high-performance EBFCs, and the other is self-powered sensors based on EBFCs. This article reviews the applied nanomaterials based on the working principle of EBFCs, analyzes the design ideas of self-powered sensors based on enzyme biofuel cells, and looks forward to their future research directions and application prospects. This article also points out the key properties of nanomaterials in EBFCs, such as electronic conductivity, biocompatibility, and catalytic activity. And the research on EBFCs is classified according to different research goals, such as improving battery efficiency, expanding the fuel range, and achieving self-powered sensors.