Xiong Liu, Li Zhao, Fangfei Liu et al.

Coordination Chemistry Reviews • 2020

Shoujie Guan, Jiaxuan Li, Yuyang Wang et al.

Advanced Materials • 2023

As an efficient alternative for harnessing the energy from human's biofluid, a wearable energy harvesting-storage hybrid supercapacitor-biofuel cell (SC-BFC) microfluidic system is established with one multifunctional electrode. The electrode integrates metal-organic framework (MOF) derived carbon nanoarrays with embedded Au, Co nanoparticles on a flexible substrate, and is used for the symmetric supercapacitor as well as the enzyme nanocarriers of the biofuel cell. The electrochemical performance of the proposed electrode is evaluated, and the corresponding working mechanism is studied in depth according to the cyclic voltammetry and density functional theory calculation. The multiplexed microfluidic system is designed to pump and store natural sweat to maintain the continuous biofuel supply in the hybrid SC-BFC system. The biofuel cell module harvests electricity from lactate in sweat, and the symmetric supercapacitor module accommodates the bioelectricity for subsequent utilization. A numerical model is developed to validate the normal operation in poor and rich sweat under variable situations for the microfluidic system. One single SC-BFC unit can be self-charged to ≈0.8 V with superior mechanical durability in on-body testing, as well as energy and power values of 7.2 mJ and 80.3 µW, respectively. It illustrates the promising scenery of energy harvesting-storage hybrid microfluidic system.

Byoung Chan Kim, In‐Seon Lee, Seok‐Joon Kwon et al.

Scientific Reports • 2017

CNTs need to be dispersed in aqueous solution for their successful use, and most methods to disperse CNTs rely on tedious and time-consuming acid-based oxidation. Here, we report the simple dispersion of intact multi-walled carbon nanotubes (CNTs) by adding them directly into an aqueous solution of glucose oxidase (GOx), resulting in simultaneous CNT dispersion and facile enzyme immobilization through sequential enzyme adsorption, precipitation, and crosslinking (EAPC). The EAPC achieved high enzyme loading and stability because of crosslinked enzyme coatings on intact CNTs, while obviating the chemical pretreatment that can seriously damage the electron conductivity of CNTs. EAPC-driven GOx activity was 4.5- and 11-times higher than those of covalently-attached GOx (CA) on acid-treated CNTs and simply-adsorbed GOx (ADS) on intact CNTs, respectively. EAPC showed no decrease of GOx activity for 270 days. EAPC was employed to prepare the enzyme anodes for biofuel cells, and the EAPC anode produced 7.5-times higher power output than the CA anode. Even with a higher amount of bound non-conductive enzymes, the EAPC anode showed 1.7-fold higher electron transfer rate than the CA anode. The EAPC on intact CNTs can improve enzyme loading and stability with key routes of improved electron transfer in various biosensing and bioelectronics devices.

Fei Shen, Dmitry Pankratov, Arnab Halder et al.

Nanoscale Advances • 2019

Application of enzymatic biofuel cells (EBFCs) in wearable or implantable biomedical devices requires flexible and biocompatible electrode materials. To this end, freestanding and low-cost graphene paper is emerging among the most promising support materials. In this work, we have exploited the potential of using graphene paper with a two-dimensional active surface (2D-GP) as a carrier for enzyme immobilization to fabricate EBFCs, representing the first case of flexible graphene papers directly used in EBFCs. The 2D-GP electrodes were prepared via the assembly of graphene oxide (GO) nanosheets into a paper-like architecture, followed by reduction to form layered and cross-linked networks with good mechanical strength, high conductivity and little dependence on the degree of mechanical bending. 2D-GP electrodes served as both a current collector and an enzyme loading substrate that can be used directly as a bioanode and biocathode. Pyrroloquinoline quinone dependent glucose dehydrogenase (PQQ-GDH) and bilirubin oxidase (BOx) adsorbed on the 2D-GP electrodes both retain their biocatalytic activities. Electron transfer (ET) at the bioanode required Meldola blue (MB) as an ET mediator to shuttle electrons between PQQ-GDH and the electrode, but direct electron transfer (DET) at the biocathode was achieved. The resulting glucose/oxygen EBFC displayed a notable mechanical flexibility, with a wide open circuit voltage range up to 0.665 V and a maximum power density of approximately 4 μW cm -2 both fully competitive with reported values for related EBFCs, and with mechanical flexibility and facile enzyme immobilization as novel merits.

Xingxing Gu, Chuan‐Jia Tong, Sarish Rehman et al.

ACS Applied Materials & Interfaces • 2016

Low-cost, long-life, and high-performance lithium batteries not only provide an economically viable power source to electric vehicles and smart electricity grids but also address the issues of the energy shortage and environmental sustainability. Herein, low-cost, hierarchically porous, and nitrogen-doped loofah sponge carbon (N-LSC) derived from the loofah sponge has been synthesized via a simple calcining process and then applied as a multifunctional blocking layer for Li-S, Li-Se, and Li-I2 batteries. As a result of the ultrahigh specific area (2551.06 m(2) g(-1)), high porosity (1.75 cm(3) g(-1)), high conductivity (1170 S m(-1)), and heteroatoms doping of N-LSC, the resultant Li-S, Li-Se, and Li-I2 batteries with the N-LSC-900 membrane deliver outstanding electrochemical performance stability in all cases, i.e., high reversible capacities of 623.6 mA h g(-1) at 1675 mA g(-1) after 500 cycles, 350 mA h g(-1) at 1356 mA g(-1) after 1000 cycles, and 150 mA h g(-1) at 10550 mA g(-1) after 5000 cycles, respectively. The successful application to Li-S, Li-Se, and Li-I2 batteries suggests that loofa sponge carbon could play a vital role in modern rechargeable battery industries as a universal, cost-effective, environmentally friendly, and high-performance blocking layer.

Yongqiang Shi, Zhihua Li, Jiyong Shi et al.

Sensors and Actuators B Chemical • 2018

Fariba Mashayekhi Mazar, José G. Martínez, Manav Tyagi et al.

Advanced Materials • 2019

Untethered actuation is important for robotic devices to achieve autonomous motion, which is typically enabled by using batteries. Using enzymes to provide the required electrical charge is particularly interesting as it will enable direct harvesting of fuel components from a surrounding fluid. Here, a soft artificial muscle is presented, which uses the biofuel glucose in the presence of oxygen. Glucose oxidase and laccase enzymes integrated in the actuator catalytically convert glucose and oxygen into electrical power that in turn is converted into movement by the electroactive polymer polypyrrole causing the actuator to bend. The integrated bioelectrode pair shows a maximum open-circuit voltage of 0.70 ± 0.04 V at room temperature and a maximum power density of 0.27 µW cm -2 at 0.50 V, sufficient to drive an external polypyrrole-based trilayer artificial muscle. Next, the enzymes are fully integrated into the artificial muscle, resulting in an autonomously powered actuator that can bend reversibly in both directions driven by glucose and O 2 only. This autonomously powered artificial muscle can be of great interest for soft (micro-)robotics and implantable or ingestible medical devices manoeuvring throughout the body, for devices in regenerative medicine, wearables, and environmental monitoring devices operating autonomously in aqueous environments.

Ruma Perveen, Inamuddin Inamuddin, Sufia ul Haque et al.

Scientific Reports • 2017

The proposed work intended to make an intellectual contribution to the domain of green nanotechnology which emphasizes the chemical synthesis of a conducting nanocomposite based on the incorporation of gold nanoparticles (Au) into the redox matrix of polyindole (PIn) along with the subsequent improvement in the overall properties of the composite by the addition of sulfonated graphene oxide (SGO). The bioanode was developed by the deposition of the PIn-Au-SGO nanocomposite with subsequent immobilization of ferritin (Frt) and glucose oxidase (GOx) on the glassy carbon electrode (GC). The successful application of the PIn-Au-SGO nanocomposite toward the development of a ferritin-mediated glucose biofuel cell anode was studied by the electrochemical characterization of the constructed bioanode (GC-PIn-Au-SGO/Frt/GOx) for the bioelectrocatalytic oxidation of glucose. The maximum current density obtained by the modified bioanode was found to be 17.8 mA cm -2 at the limiting glucose concentration of 50 mM in 0.1 M K 4 Fe(CN) 6 at a scan rate of 100 mVs -1 . The lifetime of the concerned bioelectrode when stored at 4 °C was estimated to be 53 days approximately. The appreciable results of the structural and electrochemical characterization of the PIn-Au-SGO based bioelectrode reveal its potential applications exclusively in implantable medical devices.

S. Sundaram, Md Motaher Hossain, Muhammad Rezki et al.

Biosensors • 2023

Nanomaterials, including carbon nanotubes, graphene oxide, metal-organic frameworks, metal nanoparticles, and porous carbon, play a crucial role as efficient carriers to enhance enzyme activity through substrate channeling while improving enzyme stability and reusability. However, there are significant debates surrounding aspects such as enzyme orientation, enzyme loading, retention of enzyme activity, and immobilization techniques. Consequently, these subjects have become the focus of intensive research in the realm of multi-enzyme cascade reactions. Researchers have undertaken the challenge of creating functional in vitro multi-enzyme systems, drawing inspiration from natural multi-enzyme processes within living organisms. Substantial progress has been achieved in designing multi-step reactions that harness the synthetic capabilities of various enzymes, particularly in applications such as biomarker detection (e.g., biosensors) and the development of biofuel cells. This review provides an overview of recent developments in concurrent and sequential approaches involving two or more enzymes in sequence. It delves into the intricacies of multi-enzyme cascade reactions conducted on nanostructured electrodes, addressing both the challenges encountered and the innovative solutions devised in this field.

Mohammad Faisal Umar, Abu Nasar

Applied Water Science • 2018

In the present work, a novel biosensor (GCE/RGO/PPy/NR) based on the nanocomposite of reduced graphene oxide (RGO), polypyrrole (PPy) immobilized by nitrate reductase (NR) was developed on a glassy carbon electrode (GCE). The conductive nanocomposite (RGO/PPy) was synthesized by in situ oxidative polymerization of pyrrole in the presence of RGO in acidic medium. A facile and green path was employed to synthesize RGO from graphene oxide (GO). This was performed by a novel route using Abelmoschus esculentus vegetable extract as a stabilizing and reducing agent for GO. The composite of reduced graphene oxide and polypyrrole (RGO/PPy) was deposited onto GCE with subsequent deposition of NR enzyme on the GCE/ RGO/PPy to develop GCE/RGO/PPy/NR biosensor. The surface morphology and structural features of the composites were studied by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical behavior and electrocatalytic activity of the biosensor were examined by cyclic voltammetry at different scan rates (20-100 mV s -1 ) in the synthetic nitrate solution. The developed bio-anode achieved a maximum current density of 4.24 mA cm -2 at a scan rate of 100 mV s -1 for 10 mM sodium nitrate solution.

Kornautchaya Veenuttranon, Kanyawee Kaewpradub, Itthipon Jeerapan

Nano-Micro Letters • 2023

Developing flexible bioelectronics is essential to the realization of artificial intelligence devices and biomedical applications, such as wearables, but their potential is limited by sustainable energy supply. An enzymatic biofuel cell (BFC) is promising for power supply, but its use is limited by the challenges of incorporating multiple enzymes and rigid platforms. This paper shows the first example of screen-printable nanocomposite inks engineered for a single-enzyme-based energy-harvesting device and a self-powered biosensor driven by glucose on bioanode and biocathode. The anode ink is modified with naphthoquinone and multiwalled carbon nanotubes (MWCNTs), whereas the cathode ink is modified with Prussian blue/MWCNT hybrid before immobilizing with glucose oxidase. The flexible bioanode and the biocathode consume glucose. This BFC yields an open circuit voltage of 0.45 V and a maximum power density of 266 μW cm -2 . The wearable device coupled with a wireless portable system can convert chemical energy into electric energy and detect glucose in artificial sweat. The self-powered sensor can detect glucose concentrations up to 10 mM. Common interfering substances, including lactate, uric acid, ascorbic acid, and creatinine, have no effect on this self-powered biosensor. Additionally, the device can endure multiple mechanical deformations. New advances in ink development and flexible platforms enable a wide range of applications, including on-body electronics, self-sustainable applications, and smart fabrics.

Wenyuan Liu, Pengbo Fu, Yayun Zhang et al.

Proceedings of the National Academy of Sciences • 2023

Efficient H 2 harvesting from wastewater instead of pure water can minimize fresh water consumption, which is expected to solve the problem of water shortage in H 2 production process and contribute to carbon neutrality in the environmental remediation, but the inevitable electron depletion caused by electron-consuming pollutants will result in an exhausted H 2 evolution reaction (HER) performance. In this paper, by coupling piezocatalysis and advanced oxidation processes (AOPs) by a MoS 2 /Fe 0 /peroxymonosulfate (PMS) ternary system, extensive types of wastewater achieved considerable H 2 generation, which exceeded the yield in pure water with synchronous advanced degradation of organic pollutants. In addition, profiting from the crucial bridging role of PMS, the H 2 yield in nitrobenzene wastewater after the introduction of PMS-based AOPs increased 3.37-fold from 267.7 μmol·g -1 ·h -1 to 901.0 μmol·g -1 ·h -1 because the presence of PMS both thermodynamically benefited MoS 2 piezocatalytic H 2 evolution and eliminated the electron depletion caused by organic pollutants. By this way, the original repressed H 2 evolution performance in substrate of wastewater not only was regained but even showed a significant enhancement than that in pure water (505.7 μmol·g -1 ·h -1 ). Additionally, the cyclonic piezoelectric reactor was preliminarily designed for future industrialization. This strategy provided a valuable path for the recycling of actual wastewater by fuel production and synchronous advanced treatment.

Jian Lv, Jian Chen, Pooi See Lee

SusMat • 2021

Abstract Charging wearable energy storage devices with bioenergy from human‐body motions, biofluids, and body heat holds great potential to construct self‐powered body‐worn electronics, especially considering the ceaseless nature of human metabolic activities. To bridge the gap between human‐body bioenergy and storage of energy, wearable triboelectric/piezoelectric nanogenerators (TENGs/PENGs), biofuel cells (BFCs), thermoelectric generators (TEGs) have been designed to harvest energy from body‐motions, biofluids, and body heat, respectively. Researchers have explored various strategies using bioenergy harvesters to charge wearable supercapacitors and batteries to relieve or even fully eliminate the recharging process from external power stations, thus, making wearable electronics more sustainable, autonomous, and user friendly. In this article, we review the advances in the design of sustainable energy storage devices charged by human‐body energy harvesters. The progress in multifunctional wearable energy storage devices that cater to the easy integration with human‐body energy harvesters will be summarized. Then, the focus is laid on the integrating strategies (single‐cell strategy and separated‐cell strategy), device design, materials selection, and characteristics of different self‐charging human‐body energy harvesting‐storage systems. Finally, the challenges that impede the wide application of human‐body energy harvesters charged supercapacitors/batteries and prospects will be discussed both from materials and structural design aspects.

Yichen Gong, Hongliang Han, Zhanfang Ma

Analytical and Bioanalytical Chemistry • 2023

Sufia ul Haque, Abu Nasar, Inamuddin Inamuddin et al.

Scientific Reports • 2020

A glassy carbon electrode (GC) immobilized with chitosan (CHI)@reduced graphene (rGO)-polyaniline (PAni)/ferritin (Frt)/glucose oxidase (GOx) bioelectrode was prepared. The prepared electrode was characterized by using cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) techniques. The morphological characterization was made by scanning electron microsopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. This bioelectrode provided a stable current response of 3.5 ± 0.02 mAcm -2 in 20 mM glucose. The coverage of enzyme on 0.07 cm 2 area of electrode modified with CHI@rGO-PAni/Frt was calculated to be 3.80 × 10 -8 mol cm -2 .

Giti Paimard, Ehsan Ghasali, Mireia Baeza

Chemosensors • 2023

As electrochemical measuring instruments, screen-printed electrodes (SPEs) are constructed via a technology called thick film deposition onto plastic or ceramic substrates, allowing for simple, inexpensive, and rapid on-site analysis with high reproducibility, sensitivity, and accuracy. Numerous substances such as gold, silver, platinum, and carbon are applied for electrode construction, enabling the analyst to design the best device based on its purpose to determine an analyte’s selectivity and sensitivity. Thus, in the current review, we report the latest results and analyses conducted over the past eight years (2015–2022) on the expansion of SPE electrochemical biosensors, including aptasensors, immunosensors, DNA sensors, and enzymatic biosensors. Such expansion has resulted in new possibilities for the identification, distinction, and quantification of biocompounds, drugs, enzymes, etc. Therefore, in this paper, we review the role of different nanomaterials in manufacturing on-screen electrode methods as well as strategies for the future stable diagnosis of biorecognition elements.

Md Faruk Hossain, Gymama Slaughter

2021 IEEE Sensors • 2021

A glucose biofuel cell is presented using laser induced 3D graphene (LIG) substrate integrated with catalytic active nanomaterials for harnessing the biochemical energy of glucose. The LIG anode comprised glucose dehydrogenase immobilized on reduced graphene oxide and multiwalled carbon nanotubes (RGO/MWCNTs) nanocomposite for glucose oxidation. The LIG cathode is modified with RGO/MWCNTs and silver oxide (Ag 2 O) nanocomposites for the reduction of oxygen. The assembled biofuel cell exhibited a linear peak power response up to 18 mM glucose with sensitivity of 0.63 μW mM -1 cm −2 and exhibited good linearity (r 2 = 0.99). The glucose biofuel cell showed an open-circuit voltage of 0.365 V, a maximum power density of 11.3 μW cm −2 at a cell voltage of 0.25 V, and a short-circuit current density of 45.18 μA cm −2 when operating in 18 mM glucose. Cyclic voltammetry revealed the bioanode exhibited similar linearity for the detection of glucose. These results demonstrate that LIG based bioelectrodes offer great promise for diverse applications in the development of hybrid biofuel cell and biosensor technology.

Inamuddin Inamuddin, Nimra Shakeel, Mohd Imran Ahamed et al.

Scientific Reports • 2020

Presently, one of the most important aspects for the development of enzymatic biofuel cells (EBFCs) is to synthesize the novel electrode materials that possess high current density, low open-circuit voltage (OCV) and long-term stability. To achieve the above attributes, lots of new strategies are being used by the researchers for the development of advanced materials. Nowadays, nanomaterials and nanocomposites are the promising material that has been utilized as effective electrode material in solar cells, supercapacitors and biofuel cells application. Herein, we account for a novel electrocatalyst as electrode material that comprised ZnO nanoparticles decorated on the surface of polyindole (PIn)-multi-walled carbon nanotube (MWCNT), for the immobilization of glucose oxidase (GOx) enzyme and mediator (Ferritin). The PIn-MWCNT scaffold is prepared via in situ chemical oxidative polymerization of indole on the surface of MWCNT and assessed by myriad techniques. The micrograph of scanning electron microscopy (SEM) designated the interconnected morphology of MWCNTs in the polymer matrix. X-ray diffraction spectroscopy (XRD) and Fourier transform infrared spectroscopy (FTIR), confirm the crystallinity and different functional groups available in the synthesized material, respectively. The electrochemical assessment demonstrates that the ZnO/PIn-MWCNT/Frt/GOx nanobiocatalyst exhibits much higher electrocatalytic activity towards the oxidation of glucose with a maximum current density of 4.9 mA cm -2 by consuming 50 mM glucose concentration in phosphate buffer saline (PBS) (pH 7.4) as the testing solution by applying 100 mVs -1 scan rates. The outcomes reflect that the as-prepared ZnO/PIn-MWCNTs/Frt/GOx biocomposite is a promising bioanode for the development of EBFCs.

Halima Begum, Mohammad Shamsuddin Ahmed, Young‐Bae Kim

Scientific Reports • 2020

The metal-free nitrogen-doped graphitic-carbon@graphene (Ng-C@G) is prepared from a composite of polyaniline and graphene by a facile polymerization following by pyrolysis for electrochemical oxygen reduction reaction (ORR). Pyrolysis creates a sponge-like with ant-cave-architecture in the polyaniline derived nitrogenous graphitic-carbon on graphene. The nitrogenous carbon is highly graphitized and most of the nitrogen atoms are in graphitic and pyridinic forms with less oxygenated is found when pyrolyzed at 800 °C. The electrocatalytic activity of Ng-C@G-800 is even better than the benchmarked Pt/C catalyst resulting in the higher half-wave potential (8 mV) and limiting current density (0.74 mA cm -2 ) for ORR in alkaline medium. Higher catalytic performance is originated from the special porous structure at microscale level and the abundant graphitic- and pyridinic-N active sites at the nanoscale level on carbon-graphene matrix which are beneficial to the high O 2 -mass transportation to those accessible sites. Also, it possesses a higher cycle stability resulting in the negligible potential shift and slight oxidation of pyridinic-N with better tolerance to the methanol.

Yuchen Hui, Cheng Fei, Zhongguo Zhang et al.

Journal of Solid State Electrochemistry • 2024

Pavel Afanasiev, Crina Anastasescu, Razvan State et al.

Catalysts • 2023

It is well-documented that large-scale pollution generated by human activity has a dramatic impact on ecosystems. In this context, removing harmful chemicals via photocatalysis has tremendous potential as a depollution method, utilizing freely available solar light and catalytic materials with low or negligible ecotoxicity. The main drawbacks, which aren’t often addressed in the available literature, are the formation of harmful intermediate products, low reaction rates, limited catalyst stability, and difficult catalyst recovery. In most cases, published works assess the efficiency of tested photocatalysts from pollutant degradation studies, whereas identifying and quantifying by-products is not often conducted. This review summarizes the recent advances reported for the photocatalytic removal of some organic (e.g., alcohols, carboxylic acids, volatile organic compounds, phenol) and inorganic (e.g., NO3−) contaminants. The efficiency of various UV- and visible-light active photocatalysts and the reaction degradation pathways were explained, emphasizing the main factors contributing to their mineralization. The reaction mechanisms, the identification and quantification of degradation intermediates, and the implication of reactive active species (ROS) were discussed and analyzed for each category of model target pollutant. Additionally, the actual challenges and future photocatalytic approaches to improve environmental remediation were presented.

Dubbaka Vidya, Balaji Krishnamurthy

International Journal of Hydrogen Energy • 2024

Rebecka Maria Larsen Werchmeister, Jing Tang, Xinxin Xiao et al.

Journal of The Electrochemical Society • 2019

Enzyme immobilization using nanomaterials offers new approaches to enhanced bioelectrochemical performance and is essential for the preparation of bioelectrodes with high reproducibility and low cost. In this report, we describe the development of new three-dimensional (3D) bioelectrodes by immobilizing a "bioink" of glucose oxidase (GOD) in a matrix of reduced graphene oxides (RGOs), polyethylenimine (PEI), and ferrocene carboxylic acid (FcCOOH) on carbon paper (CP). CP with 3D interwoven carbon fibers serves as a solid porous and electronically conducting skeleton, providing large surface areas and space for loading the bioink and diffusion of substrate molecules, respectively. RGO enhances contact between the GOD-matrix and CP, maintaining high conductivity. The composition of the bioink has been systematically optimized. The GOD bioelectrodes show linearly increasing electrocatalytic oxidation current toward glucose concentration up to 48 mM. A hybrid enzymatic biofuel cell equipped with the GOD bioelectrode as a bioanode and a platinum cathode furthermore registers a maximum power density of 5.1 mu W cm(-2) and an open circuit voltage of 0.40 V at 25 degrees C. The new method reported of preparing a bioelectrode by drop-casting the bioink onto the substrate electrode is facile and versatile, with the potential of application also for other enzymatic bioelectrodes.

Yuchen Hui, Huixin Wang, Wei Zuo et al.

International Journal of Hydrogen Energy • 2021

Mohammad Luqman, Mathkar A. Alharthi, Nimra Shakeel et al.

Materials Science and Engineering B • 2023

Yexin Dai, Shengling Li, Yajing Guo et al.

Journal of Power Sources • 2021

Maysam Ashrafi, Abdollah Salimi, Abbas Arabzadeh

Journal of Electroanalytical Chemistry • 2016

Md Humayun Kabir, Erik Marquez, Grace B. Djokoto et al.

ACS Applied Materials & Interfaces • 2022

Harnessing electrochemical energy in an engineered electrical circuit from biochemical substrates in the human body using biofuel cells is gaining increasing research attention in the current decade due to the wide range of biomedical possibilities it creates for electronic devices. In this report, we describe and characterize the construction of just such an enzymatic biofuel cell (EBFC). It is simple, mediator-free, and glucose-powered, employing only biocompatible materials. A novel feature is the two-dimensional mesoporous thermally reduced graphene oxide (rGO) host electrode. An additionally novelty is that we explored the potential of using biocompatible, low-cost filter paper (FP) instead of carbon paper, a conductive polymer, or gold as support for the host electrode. Using glucose (C 6 H 12 O 6 ) and molecular oxygen (O 2 ) as the power-generating fuel, the cell consists of a pair of bioelectrodes incorporating immobilized enzymes, the bioanode modified by rGO-glucose oxidase (GOx/rGO), and the biocathode modified by rGO-laccase (Lac/rGO). Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX), transmission electron microscopy, and Raman spectroscopy techniques have been employed to investigate the surface morphology, defects, and chemical structure of rGO, GOx/rGO, and Lac/rGO. N 2 sorption, SEM/EDX, and powder X-ray diffraction revealed a high Brunauer-Emmett-Teller surface area (179 m 2 g -1 ) mesoporous rGO structure with the high C/O ratio of 80:1 as well. Results from the Fourier transform infrared spectroscopy, UV-visible spectroscopy, and electrochemical impedance spectroscopy studies indicated that GOx remained in its native biochemical functional form upon being embedded onto the rGO matrix. Cyclic voltammetry studies showed that the presence of mesoporous rGO greatly enhanced the direct electrochemistry and electrocatalytic properties of the GOx/rGO and Lac/rGO nanocomposites. The electron transfer rate constant between GOx and rGO was estimated to be 2.14 s -1 . The fabricated EBFC (GOx/rGO/FP-Lac/rGO/FP) using a single GOx/rGO/FP bioanode and a single Lac/rGO/FP biocathode provides a maximum power density ( P max ) of 4.0 nW cm -2 with an open-circuit voltage ( V OC ) of 0.04 V and remains stable for more than 15 days with a power output of ∼9.0 nW cm -2 at a pH of 7.4 under ambient conditions.

Rurika Toda, Ryoichi Tatara, Tatsuo Horiba et al.

ChemElectroChem • 2021

Abstract A new multi‐enzyme bioanode utilising starch, maltose, and glucose as fuels is demonstrated. The unique combination of α‐amylase, glucoamylase, mutarotase, and flavin‐adenine dinucleotide‐dependent glucose dehydrogenase enables the bioanode to utilise a polysaccharide, starch, as a fuel. Replacing α‐amylase and glucoamylase with β‐amylase and maltase does not lead to effective starch degradation, possibly because of termination of the cleaving reaction by β‐AMY at the branching point of the starch molecules. Furthermore, by using a reduced graphene oxide/multi‐walled carbon nanotubes composite as the carbon support for enzyme immobilisation, the new bioanode demonstrates a high oxidation current density of 5.8 mA cm −2 in neutral phosphate‐buffered solution containing 0.8 % (w/v) starch. Finally, a bioanode containing the six enzymes, α‐amylase, β‐amylase, glucoamylase, maltase, mutarotase, and flavin adenine dependent glucose dehydrogenase, is fabricated. The fabricated bioanode is effective in degrading glucose, maltose, and starch. Thus, this study provides an important fundamental strategy for controlling the applicability of bioanodes by adjusting the loaded enzymes.

Fariba Mashayekhi Mazar, Mahdi Alijanianzadeh, Ahmad Molaei Rad et al.

Microelectronic Engineering • 2019

Fariba Mashayekhi Mazar, Mahdi Alijanianzadeh, Ahmad Molaeirad et al.

Process Biochemistry • 2017

Jaroslav Filip, Anita Andicsovà‐Eckstein, Alica Vikartovská et al.

Biosensors and Bioelectronics • 2016

Saithip Pakapongpan, Adisorn Tuantranont, Rungtiva P. Poo-arporn

Scientific Reports • 2017

In this work, an enzymatic biofuel cell (EBC) based on a membraneless and mediatorless glucose enzymatic fuel cell system was constructed for operation in physiological conditions (pH 7.0 and temperature 37 °C). The new platform EBC made of nanocomposite, including magnetic nanoparticles (Fe 3 O 4 NPs) and reduced graphene oxide (RGO), was used for the immobilization of glucose oxidase (GOD) as bioanode and bilirubin oxidase (BOD) as biocathode. The EBC bioelectrodes were fabricated without binder or adhesive agents for immobilized enzyme and the first EBC using superparamagnetic properties with Fe 3 O 4 NPs has been reported. The performance of the EBC was evaluated with promising results. In EBC tests, the maximum power density of the EBC was 73.7 μW cm -2 and an open circuit voltage (OCV) as +0.63 V with 5 mM of glucose concentration for the physiological condition of humans. The Fe 3 O 4 -RGO nanocomposite offers remarkable enhancement in large surface areas, is a favorable environment for enzyme immobilization, and facilitates electron transfer between enzymes and electrode surfaces. Fe 3 O 4 and RGO have been implied as new promising composite nanomaterials for immobilizing enzymes and efficient platforms due to their superparamagnetism properties. Thus, glucose EBCs could potentially be used as self-powered biosensors or electric power sources for biomedical device applications.

Omer Sadak

Nanocomposites • 2021

A nanocomposite, rGO/AuNPs, was synthesized simultaneously using one-pot approach with gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) within gelatin which used as a reducing and stabilizing agent. Then, the fabricated nanocomposites were characterized by UV-Vis, transmission electron microscope (TEM) and field emission scanning electron microscope (FE-SEM). The optimal nanocomposite was determined using electrochemical approaches. After facile and eco-friendly synthesis of rGO/AuNPs nanocomposites, it was used to fabricate the bioanode of enzymatic glucose biosensors. After drop-casting the nanocomposites on a screen-printed electrode (SPE), the glucose oxidase (GOx) was immobilized on the pre-treated SPE through a protein cross-linking approach using glutaraldehyde (GA) as a crosslinking reagent and 2,5-dihydroxybenzaldehyde (DHB) as a mediator to improve the electrochemical performance. Then, electrochemical performance of enzyme immobilized nanocomposites was studied using the potentiostat. The results demonstrate that the enzymatic biosensor made of rGO/AuNPs nanocomposites showed enhanced the sensitivity of selectivity for detection of glucose.

Yin Song, Chunlei Wang

Microsystems & Nanoengineering • 2019

Miniaturized enzymatic biofuel cells (EBFCs) with high cell performance are promising candidates for powering next-generation implantable medical devices. Here, we report a closed-loop theoretical and experimental study on a micro EBFC system based on three-dimensional (3D) carbon micropillar arrays coated with reduced graphene oxide (rGO), carbon nanotubes (CNTs), and a biocatalyst composite. The fabrication process of this system combines the top-down carbon microelectromechanical systems (C-MEMS) technique to fabricate the 3D micropillar array platform and bottom-up electrophoretic deposition (EPD) to deposit the reduced rGO/CNTs/enzyme onto the electrode surface. The Michaelis-Menten constant K M of 2.1 mM for glucose oxidase (GOx) on the rGO/CNTs/GOx bioanode was obtained, which is close to the K M for free GOx. Theoretical modelling of the rGO/CNT-based EBFC system via finite element analysis was conducted to predict the cell performance and efficiency. The experimental results from the developed rGO/CNT-based EBFC showed a maximum power density of 196.04 µW cm -2 at 0.61 V, which is approximately twice the maximum power density obtained from the rGO-based EBFC. The experimental power density is noted to be 71.1% of the theoretical value.

Inamuddin Inamuddin, Nimra Shakeel

Scientific Reports • 2020

The present study reports a new nanocomposite design using surface modified silver nanowires decorated on the surface of polyethyleneimine (PEI), a cationic polymer acting as glue for anchoring nanowires and reduced graphene oxide (rGO). The synthesized nanocomposite was employed as a promising electrode material for immobilization of biomolecules and effective transportation of electron, in enzymatic biofuel cell (EBFCs) application. The synthesized nanocomposite was confirmed by analytical techniques, for instance, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The electrochemical behaviour of the nanobioelectrocatalysts rGO-PEI/Frt/GOx, rGO-PEI/AgNWs/Frt/GOx, and rGO-PEI/Naph-SH/AgNWs/Frt/GOx was determined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). The maximum current density obtained by the modified bioanode was found to be 19.9 mA cm -2 at the limiting glucose concentration of 50 mM in PBS (pH 7.0) as supporting electrolyte at a scan rate of 100 mVs -1 .

Nimra Shakeel, Mohd Imran Ahamed, Anees Ahmed et al.

International Journal of Hydrogen Energy • 2019

Mathkar A. Alharthi, Mohammad Luqman, Nimra Shakeel et al.

Journal of nanostructure in chemistry • 2022

Grzegorz Pasternak, Yuejiao Yang, Bruno Bosquiroli Santos et al.

Bioelectrochemistry • 2018

In recent years novel applications of bioelectrochemical systems are exemplified by phototrophic biocathodes, biocompatible enzymatic fuel cells and biodegradable microbial fuel cells (MFCs). Herein, transparent silk fibroin membranes (SFM) with various fibroin content (2%, 4% and 8%) were synthesised and employed as separators in MFCs and compared with standard cation exchange membranes (CEM) as a control. The highest real-time power performance of thin-film SFM was reached by 2%-SFM separators: 25.7 ± 7.4 μW, which corresponds to 68% of the performance of the CEM separators (37.7 ± 3.1 μW). Similarly, 2%-SFM revealed the highest coulombic efficiency of 6.65 ± 1.90%, 74% of the CEM efficiency. Current for 2%-SFM reached 0.25 ± 0.03 mA (86% of CEM control). Decrease of power output was observed after 23 days for 8% and 4% and was a consequence of deterioration of SFMs, determined by physical, chemical and biological studies. This is the first time that economical and transparent silk fibroin polymers were successfully employed in MFCs.

Man Zhang, Zhaokun Ma, Huaihe Song

Nanomaterials • 2021

Through one-step pyrolysis, non-noble-metal oxygen reduction reaction (ORR) electrocatalysts were constructed from ferric trichloride, melamine, and graphene nanoribbon@carbon nanotube (GNR@CNT), in which a portion of the multiwall carbon nanotube is unwrapped/unzipped radially, and thus graphene nanoribbon is exposed. In this study, Fe-N/GNR@CNT materials were used as an air-cathode electrocatalyst in microbial fuel cells (MFCs) for the first time. The Fe-N/C shows similar power generation ability to commercial Pt/C, and its electron transfer number is 3.57, indicating that the ORR process primarily occurs with 4-electron. Fe species, pyridinic-N, graphitic-N, and oxygen-containing groups existing in GNR@CNT frameworks are likely to endow the electrocatalysts with good ORR performance, suggesting that a GNR@CNT-based carbon supporter would be a good candidate for the non-precious metal catalyst to replace Pt-based precious metal.