Recent advances in enzymatic biofuel cells enabled by innovative materials and techniques

Abstract

The past few decades have seen increasingly rapid advances in the field of sustainable energy technologies. As a new bio- and eco-friendly energy source, enzymatic biofuel cells (EBFCs) have garnered significant research interest due to their capacity to power implantable bioelectronics, portable devices, and biosensors by utilizing biomass as fuel under mild circumstances. Nonetheless, numerous obstacles impeded the commercialization of EBFCs, including their relatively modest power output and poor long-term stability of enzymes. To depict the current progress of EBFC and address the challenges it faces, this review traces back the evolution of EBFC and focuses on contemporary advances such as newly emerged multi or single enzyme systems, various porous framework-enzyme composites techniques, and innovative applications. Besides emphasizing current achievements in this field, from our perspective part we also introduced novel electrode and cell design for highly effective EBFC fabrication. We believe this review will assist readers in comprehending the basic research and applications of EBFCs as well as potentially spark interdisciplinary collaboration for addressing the pressing issues in this field.

Keywords: bioelectrodes; biosensors; enzymatic biofuel cells; enzyme cascade; implanted devices; metal‐organic frameworks; single enzyme biofuel cells.

FIGURE 1

(A) Schematic of ethanol (EtOH)/O₂ fuel cell setup. (B) Schematic diagram of enzymatic biofuel cell (EBFC).

FIGURE 2

Progress in the development of enzymatic biofuel cell (EBFC) and applications. Figure created with BioRender.com.

FIGURE 3

Comparison of energy densities among several batteries and enzymatic biofuel cells (EBFCs). The number of electrons involved is indicated. Reproduced with permission.^{[ 32 ]} Copyright 2014, Springer Nature.

FIGURE 4

Cascaded oxidation of methanol coupled by cofactor regeneration system. Reproduced with permission.^{[ 53 ]} Copyright 1998, Elsevier. ADH, alcohol dehydrogenase; FDH, fructose dehydrogenase.

FIGURE 5

(A) Schematic of enzyme cascade oxidation pathway of glucose. Reproduced with permission.^{[ 56 ]} Copyright 2012, American Chemical Society. (B) Complete oxidization glucose and xylose pathway. Reproduced with permission.^{[ 57 ]} Copyright 2022, Elsevier. (C) Schematic of enzyme cascade oxidation of xylose. Reproduced with permission.^{[ 58 ]} Copyright 2018, Wiley‐VCH.

FIGURE 6

(A) Illustration of single enzyme biofuel cell powered by bisphenol‐A (BPA). Reproduced with permission.^{[ 62 ]} Copyright 2017, Wiley‐VCH. (B) CV of enzyme loaded carbon nanotube (CNT) electrodes (curve 1), CNT electrodes (curve 2), and benchmark (curve 3) electrodes at the same sweep rate. Reproduced with permission.^{[ 62 ]} Copyright 2017, Wiley‐VCH. (C) The working voltage of the cell. Reproduced with permission.^{[ 62 ]} Copyright 2017, Wiley‐VCH. (D) Fabrication of GR/PB‐PPCA/PPCA–glucose oxidase (GOx) biocathode. Reproduced with permission.^{[ 64 ]} Copyright 2021, Springer Nature.

FIGURE 7

NADH production system coupled with alcohol dehydrogenase for electric production Reproduced with permission.^{[ 69 ]} Copyright 2019, American Chemical Society. ADH, alcohol dehydrogenase; DH, diaphorase.

FIGURE 8

(A) Three strategies for enzyme immobilization in porous framework. Reproduced with permission.^{[ 94 ]} Copyright 2022, Elsevier. (B) Laccase entrapped in ZIF‐8 for single enzyme biofuel cell. Reproduced with permission.^{[ 63 ]} Copyright 2019, Elsevier. (C) COF‐enzyme biosensor for electrochemical measurements. Reproduced with permission.^{[ 95 ]} Copyright 2019, American Chemical Society.

FIGURE 9

(A) Power extraction from cerebrospinal fluid by an implantable enzymatic biofuel cell. Reproduced with permission.^{[ 119 ]} Copyright 2012, Public Library of Science. (B) Enzymatic biofuel cell (EBFC) is implanted in the abdominal cavity of a rabbit. Reproduced with permission.^{[ 116 ]} Copyright 2018, Elsevier. (C) Long‐period stable EBFC‐based device implanted in a rabbit. Reproduced with permission.^{[ 36 ]} Copyright 2018, Elsevier. (D) Implantation of EBFC and animal brain stimulator in a bird. Reproduced with permission.^{[ 117 ]} Copyright 2021, Elsevier.

FIGURE 10

(A) Setup of enzymatic biofuel cell (EBFC) woven on a textile cloth powering up a light‐emitting diode (LED) when a glucose solution is dropped on it. Reproduced with permission.^{[ 120b ]} Copyright 2022, Elsevier. (B) EBFC implanted in the organism as energy source for a watch. Reproduced with permission.^{[ 122 ]} Copyright 2013, Royal Society of Chemistry. GDH, glucose dehydrogenase; CNT, carbon nanotube.

FIGURE 11

Wearable devices enabled by enzymatic biofuel cell (EBFC). (A) Contact lens encapsulated EBFC. Reproduced with permission.^{[ 125 ]} Copyright 2018, American Chemical Society. (B) Wearable textile EBFCs. Reproduced with permission.^{[ 130 ]} Copyright 2014, American Chemical Society. (C) Wearable applications coupled with a skin related EBFC. Reproduced with permission.^{[ 127 ]} Copyright 2017, Royal Society of Chemistry. (D) Illustration of the epidermal tattoo like EBFC. Reproduced with permission.^{[ 126 ]} Copyright 2013, Wiley‐VCH. (E) Scheme of EBFC‐based drug release system and profiles of CVs and power density. Reproduced with permission.^{[ 129 ]} Copyright 2020, American Chemical Society.

FIGURE 12

(A) Schematic representation of direct electron transfer (DET) and mediated electron transfer (MET). Reproduced with permission.^{[ 147 ]} Copyright 2014, Elsevier. (B) Configuration of enzymatic biofuel cell utilizing ethanol as fuel for both anode and cathode. Reproduced with permission.^{[ 145a ]} Copyright 2008, Elsevier.

FIGURE 13

Schematic illustration of the strategic areas for improving enzymatic biofuel cell (EBFC) performance.

FIGURE 14

(A) Schematic of immobilization strategies of enzyme cascade inside metal‐organic framework (MOF). Reproduced with permission.^{[ 153 ]} Copyright 2020, Wiley‐VCH. (B) Schematic of incorporation of conducting polymer (CP) inside MOF. Reproduced with permission.^{[ 154 ]} Copyright 2016, American Chemical Society.

FIGURE 15

(A) Construct a series of flexible enzymatic biofuel cells (EBFCs) to obtain higher voltage. Reproduced with permission.^{[ 156 ]} Copyright 2019, American Chemical Society. (B) Illustration of microfluidic EBFCs stacking device components and the product image. Reproduced with permission.^{[ 157 ]} Copyright 2022, Elsevier. FDH, fructose dehydrogenase; BOD, bilirubin oxidase; MWCNT, multi‐walled carbon nanotube.