Functional Materials in Amperometric Sensing (eBook)

Renato Seeber, Fabio Terzi, Chiara Zanardi Department of Chemistry, University of Modena and Reggio Emilia, MODENA – Italy renato.seeber@unimore.it

Preface of the Editor 6
References 7
Contents 8
Chapter 1: Importance of Modified Electrodes in Amperometric Sensing 11
1.1 From a Look at the Historical Background to Considerations for Effective Perspectives 13
1.2 Advantages Sought with Respect to Bare Electrodes 18
1.3 General Overview of the Modifying Materials 24
1.4 Amperometric Sensing for Specific and Aspecific Analyses 29
References 30
Chapter 2: Intrinsically Conducting Polymers 32
2.1 Synthesis and Deposition of ICPs onto Electrode Surfaces 34
2.2 Polymer Doping and De-Doping 37
2.3 Principal ICPs Derivatives Used in Electroanalysis 41
2.3.1 Polypyrrole 41
2.3.2 Polyaniline 42
2.3.3 Polythiophene 43
2.3.4 Polyphenazines, Polyphenothiazines, and Polyphenoxazines 44
2.4 Applications of ICPs in Electroanalysis 44
2.4.1 Direct Detection of Organic Species 44
2.4.2 Molecularly Imprinted Polymers 49
2.4.3 Detection of Metal Ions 50
2.4.4 Electronic Tongues 54
2.4.5 Enzymatic Biosensors 55
2.4.6 Genosensors 60
References 61
Chapter 3: Redox Polymers and Metallopolymers 67
3.1 Main Characteristics of Redox Polymers 67
3.2 Preparation of Electrode Modified by RPs 70
3.3 Why Modifications with RPs? 71
3.4 RPs in Applications or Suitable for Applications: Much to Do in Electroanalysis 72
3.5 Different Species for Different Roles: RP-Based Composites 74
3.6 Prussian Blue and Analogous Transition Metal Hexacyanoferrates 75
3.7 From Pure Redox to Redox-Electronic Conduction in the Same Molecule: The Metallopolymers 79
3.8 Representative Metallopolymers 88
3.8.1 Metallocenes 90
3.8.2 Bipyridine and Terpyridine Ligands 92
3.8.3 Phenanthroline Ligand 95
3.8.4 Schiff Base Ligands 96
3.8.5 Porphyrin Rings 98
3.8.6 Phthalocyanine Ring 100
3.8.7 Cyclam Cycle 100
3.8.8 Sulphur-Based Ligands 101
3.8.9 Phosphine Ligands 101
References 102
Chapter 4: Ion Exchange Polymers 106
4.1 Polymers for Ion Exchange Voltammetry 106
4.2 Polymers for Inclusion of Redox Mediators 108
4.3 Polymers for Gas Sensors 109
4.4 Other Applications of Ion-Exchange Polymers 110
References 111
Chapter 5: Monolayers 112
5.1 Anchoring Monolayers to Substrate 113
5.2 Common Substrates for Preparation of Monolayers 117
5.2.1 Substrate Preparation 119
5.2.2 Arrangement of the Head Groups on the Substrate Surface 119
5.2.3 Adsorption Sites for the Head Groups 120
5.3 Spacers 123
5.4 Stability of the Monolayers 124
5.5 Reactivity of the Monolayers 125
5.6 Mixed Monolayers 127
5.7 Monolayers Based on Oligomers and Polymers 128
5.8 Electrochemistry of Monolayers 130
5.9 Analytical Applications 134
References 141
Chapter 6: Nanosized Materials 145
6.1 Classification of Nanosized Materials 146
6.2 Synthesis Techniques 148
6.3 Stability in Solution 151
6.4 Synthesis of Nanostructures within Templates 153
6.5 Synthesis of Polymeric Nanostructures 157
6.6 Synthesis of Metal Nano-Objects through Chemical Reduction of Metal Salts 160
6.6.1 Brust´s Method 160
6.6.2 Turkevich´s Method 162
6.7 Reactivity of the Encapsulating Agent 163
6.8 Multicomponent Materials 164
6.9 Grafting Nanosized Materials onto a Substrate 166
6.9.1 Grafting of Pre-formed Nano-Objects through Monolayers 169
6.9.2 Grafting Pre-formed Nano-Objects in the Form of Hybrid Material 170
6.9.3 Simultaneous Synthesis and Deposition of Nano-Objects 170
6.10 Electroanalytical Applications 173
6.10.1 Nanosized Materials in Electrocatalytic Reactions 173
6.10.2 Nanosized Materials in Stripping Voltammetric Techniques 175
6.10.3 Nanosized Materials in Bio-Catalytic Sensors 177
6.10.4 Nanosized Materials in Affinity Biosensors 178
6.11 Final Remarks 180
References 181
Chapter 7: Silica-Based Materials and Derivatives 188
7.1 Clays 189
7.1.1 General Aspects 189
7.1.2 Electrochemical Behavior of Clay-Modified Electrodes 192
7.1.3 Deposition of Clays on the Electrode Surfaces 196
7.1.4 Application of Clays in Electroanalysis 197
Pre-concentration 198
Electrocatalysis 200
Bio-Catalysis 202
7.2 Zeolites 204
7.2.1 General Aspects 204
7.2.2 Electrochemical Behavior of Zeolite-Modified Electrodes 205
7.2.3 Deposition of Zeolite onto Electrode Surface 207
7.2.4 Analytical Applications 208
Pre-Concentration of Analytes 209
Indirect Determination 209
Catalytic Reactions 210
Biocatalytic Reactions 212
7.3 Additional Silica-Based Materials 213
7.3.1 Silica Gel 214
7.3.2 Sol-Gel 215
Mesoporous Silica 217
References 220
About the Authors 226
About the Editor 228