A guide to the biological control over electronic systems that lead the way to wearable electronics and improved drug delivery In recent years, this area of electrochemical systems has developed rapidly and achieved significant progress. Signal-Switchable Electrochemical Systems offers an overview to the wide-variety of switchable electrochemical systems and modified electrodes. The author?a noted researcher and expert on the topic?summarizes research efforts of many groups in a range of universities and countries. The book explores various types of external signals that are able to modify electrode interfaces, for example electrical potential, magnetic field, light, as well as chemical and biochemical inputs. Multifunctional properties of the modified interfaces allow their responses to complex combinations of external signals. These are integrated with unconventional biomolecular computing systems logically processing multiple biochemical signals. This approach allows the biological control over electronic systems. The text explores the applications in different areas, including unconventional computing, biofuel cells and signal-triggered molecular release in electrochemical systems. This important guide: -Provides an overview to the biological control over electronic systems and examines the key applications in biomedicine, electrochemical energy conversion and signal-processing -Offers an important text written by a highly cited researcher and pioneer in the field -Contains a summary of research efforts of an international panel of scholars representing various universities and countries -Presents a groundbreaking book that provides an introduction to this interdisciplinary field Written for scientists working with electrochemical systems and applications with signal-responsive materials, Signal-Switchable Electrochemical Systems presents an overview of the multidisciplinary field of adaptable signal-controlled electrochemical systems and processes and highlights their key aspects and future perspectives.

Table of Contents:
Preface xi 1 Introduction 1 References 1 2 Magneto]switchable Electrodes and Electrochemical Systems 5 2.1 Introduction 5 2.2 Lateral Translocation of Magnetic Micro/nanospecies on Electrodes and Electrode Arrays 5 2.3 Vertical Translocation of Magnetic Micro/Nanospecies to and from Electrode Surfaces 11 2.4 Assembling Conducting Nanowires from Magnetic Nanoparticles in the Presence of External Magnetic Field 24 2.5 Vertical Translocation of Magnetic Hydrophobic Nanoparticles to and from Electrode Surfaces 24 2.6 Repositioning and Reorientation of Magnetic Nanowires on Electrode Surfaces 45 2.7 Integration of Magnetic Nanoparticles into Polymer]Composite Materials 49 2.8 Conclusions and Perspectives 51 2.9 Appendix: Synthesis and Properties of Magnetic Particles and Nanowires 54 References 62 Symbols and Abbreviations 69 3 Modified Electrodes and Electrochemical Systems Switchable by Temperature Changes 71 3.1 Introduction 71 3.2 Thermo]sensitive Polymers with Coil]to]Globule Transition 72 3.3 Electrode Surfaces Modified with Thermo]sensitive Polymers for Temperature]controlled Electrochemical and Bioelectrochemical Processes 74 3.4 Electrode Surfaces Modified with Multicomponent Systems Combining Thermo]sensitive Polymers with pH], Photoand Potential]Switchable Elements 79 3.4.1 Temperature] and pH]sensitive Modified Electrodes 80 3.4.2 Temperature] and Photo]sensitive Modified Electrodes 83 3.4.3 Temperature]sensitive Modified Electrodes Controlled by Complex Combinations of External Signals 89 3.5 Electrodes Modified with Thermo]switchable Polymer Films Containing Entrapped Metal Nanoparticles – Inverted Temperaturedependent Switching 93 3.6 Conclusions and Perspectives 94 References 96 Symbols and Abbreviations 98 4 Modified Electrodes and Electrochemical Systems Switchable by Light Signals 101 4.1 Introduction 101 4.2 Diarylethene]based Photoelectrochemical Switches 103 4.3 Phenoxynaphthacenequinone]based Photoelectrochemical Switches 120 4.4 Azobenzene]based Photoelectrochemical Switches 125 4.5 Spiropyran–merocyanine]based Photoelectrochemical Switches 141 4.6 Conclusions and Perspectives 158 References 159 Symbols and Abbreviations 167 5 Modified Electrodes Switchable by Applied Potentials Resulting in Electrochemical Transformations at Functional Interfaces 169 References 175 Symbols and Abbreviations 176 6 Electrochemical Systems Switchable by pH Changes 177 6.1 Introduction 177 6.2 Monolayer Modified Electrodes with Electrochemical and Electrocatalytic Activity Controlled by pH Value 178 6.3 Polymer]Brush]Modified Electrodes with Bioelectrocatalytic Activity Controlled by pH Value 179 6.4 pH]Controlled Electrode Interfaces Coupled with in situ Produced pH Changes Generated by Enzyme Reactions 186 6.5 pH]Triggered Disassembly of Biomolecular Complexes on Surfaces Resulting in Electrode Activation 188 6.6 pH]Stimulated Biomolecule Release from Polymer]Brush Modified Electrodes 190 6.7 Conclusions and Perspectives 196 References 197 Symbols and Abbreviations 201 7 Coupling of Switchable Electrodes and Electrochemical Processes with Biomolecular Computing Systems 203 7.1 Introduction 203 7.1.1 General Introduction to the Area of Enzyme]based Biocomputing (Logic) Systems 203 7.1.2 General Definitions and Approaches Used in Realization of Enzymebased Logic Systems 205 7.2 Electrochemical Analysis of Output Signals Generated by Enzyme Logic Systems 206 7.2.1 Chronoamperometric Transduction of Chemical Output Signals Produced by Enzyme]based Logic Systems 207 7.2.2 Potentiometric Transduction of Chemical Output Signals Produced by Enzyme]based Logic Systems 209 7.2.3 pH]Measurements as a Tool for Transduction of Chemical Output Signals Produced by Enzyme]based Logic Systems 209 7.2.4 Indirect Electrochemical Analysis of Output Signals Generated by Enzyme]based Logic Systems Using Electrodes Functionalized with pH]Switchable Polymers 212 7.2.5 Conductivity Measurements as a Tool for Transduction of Chemical Output Signals Produced by Enzyme]based Logic Systems 215 7.2.6 Transduction of Chemical Output Signals Produced by Enzyme]based Logic Systems Using Semiconductor Devices 218 7.3 Summary 220 References 220 Symbols and Abbreviations 226 8 Biofuel Cells with Switchable/Tunable Power Output as an Example of Implantable Bioelectronic Devices 229 8.1 General Introduction: Bioelectronics and Implantable Electronics 229 8.2 More Specific Introduction: Harvesting Power from Biological Sources – Implantable Biofuel Cells 231 8.3 Biofuel Cells with Switchable/Tunable Power Output 236 8.3.1 Switchable/Tunable Biofuel Cell Controlled by Electrical Signals 236 8.3.2 Switchable/Tunable Biofuel Cell Controlled by Magnetic Signals 239 8.3.3 Biofuel Cells Controlled by Logically Processed Biochemical Signals 242 8.4 Summary 256 References 257 Symbols and Abbreviations 260 9 Signal]triggered Release of Biomolecules from Alginate]modified Electrodes 263 9.1 Introduction – Signal]activated Biomolecular Release Processes 263 9.2 Alginate Polymer Cross]linked with Fe3+ Cations – The Convenient Matrix for Molecular Release Stimulated by Electrochemical Signal 264 9.3 Self]operating Release Systems Based on the Alginate Electrodes Integrated with Biosensing Electrodes 268 9.4 Conclusions and Perspectives 278 References 279 Symbols and Abbreviations 282 10 What is Next? Molecular Biology Brings New Ideas 285 10.1 Switchable Enzymes and Their Use in Bioelectrochemical Systems – Motivation and Applications 286 10.2 Electrocatalytic Function of the Ca2+]Switchable PQQ]GDH]CaM Chimeric Enzyme 287 10.3 Integration of the Ca2+]Switchable PQQ]GDH]CaM Chimeric Enzyme with a Semiconductor Chip 289 10.4 A Ca2+]Switchable Biofuel Cell Based on the PQQ]GDH]CaM Chimeric Enzyme 291 10.5 Substance Release System Activated with Ca2+ Cations and Based on the PQQ]GDH]CaM Chimeric Enzyme 292 10.6 Summary 294 References 294 Symbols and Abbreviations 296 11 Summary and Outlook: Scaling up the Complexity of Signal]processing Systems and Foreseeing New Applications 297 References 301 Index 303