CHEMICAL SENSORS AND BIOSENSORS -- Contents -- Series Preface -- Preface -- Acronyms, Abbreviations and Symbols -- About the Author -- 1 Introduction -- 1.1 Introduction to Sensors -- 1.1.1 What are Sensors? -- 1.1.2 The Nose as a Sensor -- 1.2 Sensors and Biosensors - Definitions -- 1.3 Aspects of Sensors -- 1.3.1 Recognition Elements -- 1.3.2 Transducers - the Detector Device -- 1.3.3 Methods of Immobilization -- 1.3.4 Performance Factors -- 1.3.5 Areas of Application -- 2 Transduction Elements -- 2.1 Electrochemical Transducers - Introduction -- 2.2 Potentiometry and Ion-Selective Electrodes: The Nernst Equation -- 2.2.1 Cells and Electrodes -- 2.2.2 Reference Electrodes -- 2.2.3 Quantitative Relationships: The Nernst Equation -- 2.2.4 Practical Aspects of Ion-Selective Electrodes -- 2.2.5 Measurement and Calibration -- 2.3 Voltammetry and Amperometry -- 2.3.1 Linear-Sweep Voltammetry -- 2.3.2 Cyclic Voltammetry -- 2.3.3 Chronoamperometry -- 2.3.4 Amperometry -- 2.3.5 Kinetic and Catalytic Effects -- 2.4 Conductivity -- 2.5 Field-Effect Transistors -- 2.5.1 Semiconductors - Introduction -- 2.5.2 Semiconductor-Solution Contact -- 2.5.3 Field-Effect Transistor -- 2.6 Modified Electrodes, Thin-Film Electrodes and Screen-Printed Electrodes -- 2.6.1 Thick-Film - Screen-Printed Electrodes -- 2.6.2 Microelectrodes -- 2.6.3 Thin-Film Electrodes -- 2.7 Photometric Sensors -- 2.7.1 Introduction -- 2.7.2 Optical Techniques -- 2.7.3 Ultraviolet and Visible Absorption Spectroscopy -- 2.7.4 Fluorescence Spectroscopy -- 2.7.5 Luminescence -- 2.7.6 Optical Transducers -- 2.7.7 Device Construction -- 2.7.8 Solid-Phase Absorption Label Sensors -- 2.7.9 Applications -- Further Reading -- 3 Sensing Elements -- 3.1 Introduction -- 3.2 Ionic Recognition -- 3.2.1 Ion-Selective Electrodes - Introduction -- 3.2.2 Interferences -- 3.2.3 Conducting Devices.

3.2.4 Modified Electrodes and Screen-Printed Electrodes -- 3.3 Molecular Recognition - Chemical Recognition Agents -- 3.3.1 Thermodynamic - Complex Formation -- 3.3.2 Kinetic-Catalytic Effects: Kinetic Selectivity -- 3.3.3 Molecular Size -- 3.4 Molecular Recognition - Spectroscopic Recognition -- 3.4.1 Introduction -- 3.4.2 Infrared Spectroscopy - Molecular -- 3.4.3 Ultraviolet Spectroscopy - Less Selective -- 3.4.4 Nuclear Magnetic Resonance Spectroscopy - Needs Interpretation -- 3.4.5 Mass Spectrometry -- 3.5 Molecular Recognition - Biological Recognition Agents -- 3.5.1 Introduction -- 3.5.2 Enzymes -- 3.5.3 Tissue Materials -- 3.5.4 Micro-Organisms -- 3.5.5 Mitochondria -- 3.5.6 Antibodies -- 3.5.7 Nucleic Acids -- 3.5.8 Receptors -- 3.6 Immobilization of Biological Components -- 3.6.1 Introduction -- 3.6.2 Adsorption -- 3.6.3 Microencapsulation -- 3.6.4 Entrapment -- 3.6.5 Cross-Linking -- 3.6.6 Covalent Bonding -- Further Reading -- 4 Performance Factors -- 4.1 Introduction -- 4.2 Selectivity -- 4.2.1 Ion-Selective Electrodes -- 4.2.2 Enzymes -- 4.2.3 Antibodies -- 4.2.4 Receptors -- 4.2.5 Others -- 4.3 Sensitivity -- 4.3.1 Range, Linear Range and Detection Limits -- 4.4 Time Factors -- 4.4.1 Response Times -- 4.4.2 Recovery Times -- 4.4.3 Lifetimes -- 4.5 Precision, Accuracy and Repeatability -- 4.6 Different Biomaterials -- 4.7 Different Transducers -- 4.7.1 Urea Biosensors -- 4.7.2 Amino Acid Biosensors -- 4.7.3 Glucose Biosensors -- 4.7.4 Uric Acid -- 4.8 Some Factors Affecting the Performance of Sensors -- 4.8.1 Amount of Enzyme -- 4.8.2 Immobilization Method -- 4.8.3 pH of Buffer -- Further Reading -- 5 Electrochemical Sensors and Biosensors -- 5.1 Potentiometric Sensors - Ion-Selective Electrodes -- 5.1.1 Concentrations and Activities -- 5.1.2 Calibration Graphs -- 5.1.3 Examples of Ion-Selective Electrodes.

5.1.4 Gas Sensors - Gas-Sensing Electrodes -- 5.2 Potentiometric Biosensors -- 5.2.1 pH-Linked -- 5.2.2 Ammonia-Linked -- 5.2.3 Carbon Dioxide-Linked -- 5.2.4 Iodine-Selective -- 5.2.5 Silver Sulfide-Linked -- 5.3 Amperometric Sensors -- 5.3.1 Direct Electrolytic Methods -- 5.3.2 The Three Generations of Biosensors -- 5.3.3 First Generation - The Oxygen Electrode -- 5.3.4 Second Generation - Mediators -- 5.3.5 Third Generation - Directly Coupled Enzyme Electrodes -- 5.3.6 NADH/NAD+ -- 5.3.7 Examples of Amperometric Biosensors -- 5.3.8 Amperometric Gas Sensors -- 5.4 Conductometric Sensors and Biosensors -- 5.4.1 Chemiresistors -- 5.4.2 Biosensors Based on Chemiresistors -- 5.4.3 Semiconducting Oxide Sensors -- 5.5 Applications of Field-Effect Transistor Sensors -- 5.5.1 Chemically Sensitive Field-Effect Transistors (CHEMFETs) -- 5.5.2 Ion-Selective Field-Effect Transistors (ISFETs) -- 5.5.3 FET-Based Biosensors (ENFETs) -- Further Reading -- 6 Photometric Applications -- 6.1 Techniques for Optical Sensors -- 6.1.1 Modes of Operation of Waveguides in Sensors -- 6. I .2 Immobilized Reagents -- 6.2 Visible Absorption Spectroscopy -- 6.2.1 Measurement of pH -- 6.2.2 Measurement of Carbon Dioxide -- 6.2.3 Measurement of Ammonia -- 6.2.4 Examples That Have Been Used in Biosensors -- 6.3 Fluorescent Reagents -- 6.3.1 Fluorescent Reagents for pH Measurements -- 6.3.2 Halides -- 6.3.3 Sodium -- 6.3.4 Potassium -- 6.3.5 Gas Sensors -- 6.4 Indirect Methods Using Competitive Binding -- 6.5 Reflectance Methods - Internal Reflectance Spectroscopy -- 6.5.1 Evanescent Waves -- 6.5.2 Reflectance Methods -- 6.5.3 Attenuated Total Reflectance -- 6.5.4 Total Internal Reflection Fluorescence -- 6.5.5 Surface Plasmon Resonance -- 6.6 Light Scattering Techniques -- 6.6.1 Types of Light Scattering -- 6.6.2 Quasi-Elastic Light Scattering Spectroscopy.

6.6.3 Photon Correlation Spectroscopy -- 6.6.4 Laser Doppler Velocimetry -- Further Reading -- 7 Mass-Sensitive and Thermal Sensors -- 7.1 The Piezo-Electric Effect -- 7.1.1 Principles -- 7.1.2 Gas Sensor Applications -- 7.1.3 Biosensor Applications -- 7.1.4 The Quartz Crystal Microbalance -- 7.2 Surface Acoustic Waves -- 7.2.1 Plate Wave Mode -- 7.2.2 Evanescent Wave Mode -- 7.2.3 Lamb Mode -- 7.2.4 Thickness Shear Mode -- 7.3 Thermal Sensors -- 7.3.1 Thermistors -- 7.3.2 Catalytic Gas Sensors -- 7.3.3 Thermal Conductivity Devices -- Further Reading -- 8 Specific Applications -- 8.1 Determination of Glucose in Blood - Amperometric Biosensor -- 8.1.1 Survey of Biosensor Methods for the Determination of Glucose -- 8.1.2 Aim -- 8.2 Determination of Nanogram Levels of Copper(1) in Water Using Anodic Stripping Voltammetry, Employing an Electrode Modified with a Complexing Agent -- 8.2.1 Background to Stripping Voltammetry - Anodic and Cathodic -- 8.2.2 Aim -- 8.3 Determination of Several Ions Simultaneously - 'The Laboratory on a Chip' -- 8.3.1 Chemiresistors -- 8.3.2 Sensor Arrays and 'Smart' Sensors -- 8.3.3 Background to Ion-Selective Field-Effect Transistors -- 8.3.4 Aim -- 8.4 Determination of Attomole Levels of a Trinitrotoluene- Antibody Complex with a Luminescent Transducer -- 8.4.1 Background to Immuno-Luminescent Assays -- 8.4.2 Aim -- 8.5 Determination of Flavanols in Beers -- 8.5.1 Background -- 8.5.2 Aim -- Further Reading -- Responses to Self-Assessment Questions -- Bibliography -- Glossary of Terms -- SI Units and Physical Constants -- Periodic Table -- Index.