Introductory Bioelectronics

About the Authors xiii

Foreword xv

Preface xvii

Acknowledgements xix

1 Basic Chemical and Biochemical Concepts 1

1.1 Chapter Overview 1

1.2 Energy and Chemical Reactions 1

1.3 Water and Hydrogen Bonds 15

1.4 Acids, Bases and pH 18

1.5 Summary of Key Concepts 25

2 Cells and their Basic Building Blocks 29

2.1 Chapter Overview 29

2.2 Lipids and Biomembranes 29

2.3 Carbohydrates and Sugars 32

2.4 Amino Acids, Polypeptides and Proteins 34

2.5 Nucleotides, Nucleic Acids, DNA, RNA and Genes 43

2.6 Cells and Pathogenic Bioparticles 51

2.7 Summary of Key Concepts 70

3 Basic Biophysical Concepts and Methods 73

3.1 Chapter Overview 73

3.2 Electrostatic Interactions 74

3.3 Hydrophobic and Hydration Forces 90

3.4 Osmolarity, Tonicity and Osmotic Pressure 91

3.5 Transport of Ions and Molecules across Cell Membranes 94

3.6 Electrochemical Gradients and Ion Distributions Across Membranes 99

3.7 Osmotic Properties of Cells 103

3.8 Probing the Electrical Properties of Cells 105

3.9 Membrane Equilibrium Potentials 111

3.10 Nernst Potential and Nernst Equation 112

3.11 The Equilibrium (Resting) Membrane Potential 114

3.12 Membrane Action Potential 116

3.13 Channel Conductance 120

3.14 The Voltage Clamp 121

3.15 Patch-Clamp Recording 122

3.16 Electrokinetic Effects 124

4 Spectroscopic Techniques 147

4.1 Chapter Overview 147

4.2 Introduction 148

4.3 Classes of Spectroscopy 151

4.4 The Beer-Lambert Law 165

4.5 Impedance Spectroscopy 170

5 Electrochemical Principles and Electrode Reactions 177

5.1 Chapter Overview 177

5.2 Introduction 178

5.3 Electrochemical Cells and Electrode Reactions 180

5.4 Electrical Control of Electron Transfer Reactions 194

5.5 Reference Electrodes 203

5.6 Electrochemical Impedance Spectroscopy (EIS) 208

6 Biosensors 215

6.1 Chapter Overview 215

6.2 Introduction 215

6.3 Immobilisation of the Biosensing Agent 217

6.4 Biosensor Parameters 218

6.5 Amperometric Biosensors 228

6.6 Potentiometric Biosensors 233

6.7 Conductometric and Impedimetric Biosensors 237

6.8 Sensors Based on Antibody-Antigen Interaction 240

6.9 Photometric Biosensors 242

6.10 Biomimetic Sensors 245

6.11 Glucose Sensors 247

6.12 Biocompatibility of Implantable Sensors 252

7 Basic Sensor Instrumentation and Electrochemical Sensor Interfaces 259

7.1 Chapter Overview 259

7.2 Transducer Basics 260

7.3 Sensor Amplification 262

7.4 The Operational Amplifier 264

7.5 Limitations of Operational Amplifiers 269

7.6 Instrumentation for Electrochemical Sensors 271

7.7 Impedance Based Biosensors 278

7.8 FET Based Biosensors 284

8 Instrumentation for Other Sensor Technologies 297

8.1 Chapter Overview 297

8.2 Temperature Sensors and Instrumentation 298

8.3 Mechanical Sensor Interfaces 304

8.4 Optical Biosensor Technology 325

8.5 Transducer Technology for Neuroscience and Medicine 335

9 Microfluidics: Basic Physics and Concepts 343

9.1 Chapter Overview 343

9.2 Liquids and Gases 343

9.3 Fluids Treated as a Continuum 346

9.4 Basic Fluidics 354

9.5 Fluid Dynamics 356

9.6 Navier-Stokes Equations 365

9.7 Continuum versus Molecular Model 369

9.8 Diffusion 378

9.9 Surface Tension 383

10 Microfluidics: Dimensional Analysis and Scaling 391

10.1 Chapter Overview 391

10.2 Dimensional Analysis 391

10.3 Dimensionless Parameters 400

10.4 Applying Nondimensional Parameters to Practical Flow Problems 411

10.5 Characteristic Time Scales 412

10.6 Applying Micro- and Nano-Physics to the Design of Microdevices 413

Problems 415

References 416

Appendix A: SI Prefixes 417

Appendix B: Values of Fundamental Physical Constants 419

Appendix C: Model Answers for Self-study Problems 421

Index 435