Enzymatic Fuel Cells

Summarizes research encompassing all of the aspects required to understand, fabricate and integrate enzymatic fuel cells

• Contributions span the fields of bio-electrochemistry and biological fuel cell research
• Teaches the reader to optimize fuel cell performance to achieve long-term operation and realize commercial applicability
• Introduces the reader to the scientific aspects of bioelectrochemistry including electrical wiring of enzymes and charge transfer in enzyme fuel cell electrodes
• Covers unique engineering problems of enzyme fuel cells such as design and optimization

Preface xv

Contributors xvii

1 Introduction 1
Heather R. Luckarift, Plamen Atanassov, and Glenn R. Johnson

List of Abbreviations 3

2 Electrochemical Evaluation of Enzymatic Fuel Cells and Figures of Merit 4
Shelley D. Minteer, Heather R. Luckarift, and Plamen Atanassov

2.1 Introduction 4

2.2 Electrochemical Characterization 5

2.3 Outlook 9

Acknowledgment 10

List of Abbreviations 10

References 10

3 Direct Bioelectrocatalysis: Oxygen Reduction for Biological Fuel Cells 12
Dmitri M. Ivnitski, Plamen Atanassov, and Heather R. Luckarift

3.1 Introduction 12

3.2 Mechanistic Studies of Intramolecular Electron Transfer 13

3.3 Achieving DET of MCO by Rational Design 18

3.4 Outlook 25

Acknowledgments 26

List of Abbreviations 26

References 27

4 Anodic Catalysts for Oxidation of Carbon-Containing Fuels 33
Rosalba A. Rincón, Carolin Lau, Plamen Atanassov, and Heather R. Luckarift

4.1 Introduction 33

4.2 Oxidases 34

4.3 Dehydrogenases 35

4.4 PQQ-Dependent Enzymes 42

4.5 Outlook 44

Acknowledgment 45

List of Abbreviations 45

References 45

5 Anodic Bioelectrocatalysis: From Metabolic Pathways to Metabolons 53
Shuai Xu, Lindsey N. Pelster, Michelle Rasmussen, and Shelley D. Minteer

5.1 Introduction 53

5.2 Biological Fuels 53

5.3 Promiscuous Enzymes Versus Multienzyme Cascades Versus Metabolons 55

5.4 Direct and Mediated Electron Transfer 57

5.5 Fuels 58

5.6 Outlook 72

Acknowledgment 72

List of Abbreviations 73

References 73

6 Bioelectrocatalysis of Hydrogen Oxidation/Reduction by Hydrogenases 80
Anne K. Jones, Arnab Dutta, Patrick Kwan, Chelsea L. McIntosh, Souvik Roy, and Sijie Yang

6.1 Introduction 80

6.2 Hydrogenases 81

6.3 Biological Fuel Cells Using Hydrogenases: Electrocatalysis 85

6.4 Electrocatalysis by Functional Mimics of Hydrogenases 92

6.5 Outlook 97

Acknowledgments 98

List of Abbreviations 98

References 99

7 Protein Engineering for Enzymatic Fuel Cells 109
Elliot Campbell and Scott Banta

7.1 Engineering Enzymes for Catalysis 109

7.2 Engineering Other Properties of Enzymes 112

7.3 Enzyme Immobilization and Self-Assembly 115

7.4 Artificial Metabolons 117

7.5 Outlook 118

List of Abbreviations 118

References 118

8 Purification and Characterization of Multicopper Oxidases for Enzyme Electrodes 123
D. Matthew Eby and Glenn R. Johnson

8.1 Introduction 123

8.2 General Considerations for MCO Expression and Purification 124

8.3 MCO Production and Expression Systems 125

8.4 MCO Purification 128

8.5 Copper Stability and Specific Considerations for MCO Production 133

8.6 Spectroscopic Monitoring and Characterization of Copper Centers 136

8.7 Outlook 139

Acknowledgment 140

List of Abbreviations 140

References 140

9 Mediated Enzyme Electrodes 146
Joshua W. Gallaway

9.1 Introduction 146

9.2 Fundamentals 147

9.3 Types of Mediation 152

9.4 Aspects of Mediator Design I: Mediator Overpotentials 162

9.5 Aspects of Mediator Design II: Saturated Mediator Kinetics 165

9.6 Outlook 172

List of Abbreviations 172

References 172

10 Hierarchical Materials Architectures for Enzymatic Fuel Cells 181
Guinevere Strack and Glenn R. Johnson

10.1 Introduction 181

10.2 Carbon Nanomaterials and the Construction of the Bio–Nano Interface 184

10.3 Biotemplating: The Assembly of Nanostructured Biological–Inorganic Materials 191

10.4 Fabrication of Hierarchically Ordered 3D Materials for Enzyme and Microbial Electrodes 194

10.5 Incorporating Conductive Polymers into Bioelectrodes for Fuel Cell Applications 198

10.6 Outlook 201

Acknowledgment 201

List of Abbreviations 201

References 202

11 Enzyme Immobilization for Biological Fuel Cell Applications 208
Lorena Betancor and Heather R. Luckarift

11.1 Introduction 208

11.2 Immobilization by Physical Methods 209

11.3 Entrapment as a Pre- and Post-Immobilization Strategy 211

11.4 Enzyme Immobilization via Chemical Methods 213

11.5 Orientation Matters 216

11.6 Outlook 218

Acknowledgment 219

List of Abbreviations 219

References 219

12 Interrogating Immobilized Enzymes in Hierarchical Structures 225
Michael J. Cooney and Heather R. Luckarift

12.1 Introduction 225

12.2 Estimating the Bound Active (Redox) Enzyme 227

12.3 Probing the Distribution of Immobilized Enzyme Within Hierarchical Structures 232

12.4 Probing the Immediate Chemical Microenvironments of Enzymes in Hierarchical Structures 235

12.5 Enzyme Aggregation in a Hierarchical Structure 236

12.6 Outlook 238

Acknowledgment 239

List of Abbreviations 239

References 239

13 Imaging and Characterization of the Bio–Nano Interface 242
Karen E. Farrington, Heather R. Luckarift, D. Matthew Eby, and Kateryna Artyushkova

13.1 Introduction 242

13.2 Imaging the Bio–Nano Interface 243

13.3 Characterizing the Bio–Nano Interface 248

13.4 Interrogating the Bio–Nano Interface 256

13.5 Outlook 267

Acknowledgment 267

List of Abbreviations 267

References 268

14 Scanning Electrochemical Microscopy for Biological Fuel Cell Characterization 273
Ramaraja P. Ramasamy

14.1 Introduction 273

14.2 Theory and Operation 274

14.3 Ultramicroelectrodes 275

14.4 Modes of SECM Operation 278

14.5 SECM for BFC Anodes 281

14.6 SECM for BFC Cathodes 285

14.7 Catalyst Screening Using SECM 290

14.8 SECM for Membranes 291

14.9 Probing Single Enzyme Molecules Using SECM 293

14.10 Combining SECM with Other Techniques 293

14.11 Outlook 297

List of Abbreviations 297

References 298

15 In Situ X-Ray Spectroscopy of Enzymatic Catalysis: Laccase-Catalyzed Oxygen Reduction 304
Sanjeev Mukerjee, Joseph Ziegelbauer, Thomas M. Arruda, Kateryna Artyushkova, and Plamen Atanassov

15.1 Introduction 304

15.2 Defining the Enzyme/Electrode Interface 305

15.3 Direct Electron Transfer Versus Mediated Electron Transfer 306

15.4 The Blue Copper Oxidases 308

15.5 In Situ XAS 310

15.6 Proposed ORR Mechanism 327

15.7 Outlook 331

Acknowledgments 331

List of Abbreviations 331

References 332

16 Enzymatic Fuel Cell Design, Operation, and Application 337
Vojtech Svoboda and Plamen Atanassov

16.1 Introduction 337

16.2 Biobatteries and EFCs 338

16.3 Components 339

16.4 Single-Cell Design 345

16.5 Microfluidic EFC Design 348

16.6 Stacked Cell Design 348

16.7 Bipolar Electrodes 350

16.8 Air/Oxygen Supply 351

16.9 Fuel Supply 351

16.10 Storage and Shelf Life 356

16.11 EFC Operation, Control, and Integration with Other Power Sources 356

16.12 EFC Control 357

16.13 Power Conditioning 357

16.14 Outlook 358

List of Abbreviations 359

References 359

17 Miniature Enzymatic Fuel Cells 361
Takeo Miyake and Matsuhiko Nishizawa

17.1 Introduction 361

17.2 Insertion MEFC 362

17.3 Microfluidic MEFC 366

17.4 Flexible Sheet MEFC 370

17.5 Outlook 371

List of Abbreviations 372

References 372

18 Switchable Electrodes and Biological Fuel Cells 374
Evgeny Katz, Vera Bocharova, and Jan Halámek

18.1 Introduction 374

18.2 Switchable Electrodes for Bioelectronic Applications 375

18.3 Light-Switchable Modified Electrodes Based on Photoisomerizable Materials 376

18.4 Magnetoswitchable Electrochemical Reactions Controlled by Magnetic Species Associated with Electrode Interfaces 378

18.5 Modified Electrodes Switchable by Applied Potentials Resulting in Electrochemical Transformations at Functional Interfaces 381

18.6 Chemically/Biochemically Switchable Electrodes 383

18.7 Coupling of Switchable Electrodes with Biomolecular Computing Systems 389

18.8 BFCs with Switchable/Tunable Power Output 396

18.9 Outlook 412

Acknowledgments 413

List of Abbreviations 413

References 414

19 Biological Fuel Cells for Biomedical Applications 422
Magnus Falk, Sergey Shleev, Claudia W. Narváez Villarrubia, Sofia Babanova, and Plamen Atanassov

19.1 Introduction 422

19.2 Definition and Classification of BFCs 424

19.3 Design Aspects of EFCs 427

19.4 In Vitro and In Vivo BFC Studies 433

19.5 Outlook 440

List of Abbreviations 442

References 443

20 Concluding Remarks and Outlook 451
Glenn R. Johnson, Heather R. Luckarift, and Plamen Atanassov

20.1 Introduction 451

20.2 Primary System Engineering: Design Determinants 453

20.3 Fundamental Advances in Bioelectrocatalysis 454

20.4 Design Opportunities from EFC Operation 454

20.5 Fundamental Drivers for EFC Miniaturization 455

20.6 Commercialization of EFCs: Strategies and Opportunities 455

Acknowledgment 457

List of Abbreviations 457

References 457

Index 459

HEATHER R. LUCKARIFT is the Senior Research Scientist for Universal Technology Corporation at the Air Force Civil Engineer Center (formerly the Microbiology & Applied Biochemistry team at the Air Force Research Laboratory). She is the author of over fifty peer-reviewed publications and invited reviews.

PLAMEN ATANASSOV is a Professor of Chemical & Nuclear Engineering and the founding director of The University of New Mexico Center for Emerging Energy Technologies. He was the principal investigator on an Air Force Office of Scientific Research Multi-University Research Initiative program: “Fundamentals and Bioengineering of Enzymatic Fuel Cells.” He is the author of more than 220 publications, including twelve reviews.

GLENN R. JOHNSON is the Chief Scientist and founder of Hexpoint Technologies and the former principal investigator of the Microbiology & Applied Biochemistry team within the Air Force Research Laboratory. He is the author of over fifty peer-reviewed publications and invited reviews.

A thorough and illuminating look at enzymatic fuel cells and their place in our current and future world

With their use in biomedical applications and for portable electronics, enzymatic fuel cells offer an alternative power source to meet our world’s increasing energy demands.

Outlining the fundamentals, design, optimization, integration, and future trends of enzymatic fuel cells, Enzymatic Fuel Cells: From Fundamentals to Applications presents a comprehensive overview of enzymatic fuel cell research—with a special emphasis on methodology, fabrication, integration, and testing of enzymatic fuel cells.

The book provides introductory reading with a concise scheme of illustrations and:

• Covers fundamentals of enzymatic fuel cells as well as their design, optimization, and integration
• Introduces the reader to the scientific aspects of bioelectrochemistry and the unique engineering problems of enzymatic fuel cells
• Offers an outlook on the practical applications of enzymatic fuel cells such as powering of microdevices, biomedical applications, and in autonomous systems
• Details future developments and emerging applications of enzymatic fuel cells

Enzymatic Fuel Cells is an ideal book for readers in the areas of electrochemistry, biochemistry, materials science, biosensors, biotechnology, environmental and chemical engineering, wastewater, and biology.