Optical Guided-wave Chemical and Biosensors II (eBook)

Preface 8
Contents of Volume II 8
Contents of Volume I 8
Part I Waveguide Sensors with Periodic Structures 16
Nano-structured Silicon Optical Sensors 17
Introduction 18
Origins and Definitions 19
Types of PSi Sensors 20
Porous Silicon Sensing with Single-Layer Interferometers 20
Rugate Filters 21
Multilayer Devices: Bragg Reflector 21
Multilayer Devices: Thue-Morse Sequence 21
Porous Silicon Microcavities in Meso- and Macroporous Silicon: Further Confinement of Light 22
Double-Layer, Self-Referenced PSi Sensors 26
Special Applications: Monitoring Peptide Synthesis 27
Characterizing Porous Silicon Via Enzymatic Reactions 28
Characterizing Enzymatic Reactions with Porous Silicon 29
Detection of Small-Molecule Analytes 29
Monitoring Diffusion out of a Sensor for Drug Delivery 31
Alternative Sensor Configurations: Waveguides 31
Towards In Vivo Applications: Enhancing the Stability of PSi Via Surface Derivatization 32
Sensor Infiltration and Sensor Efficiency 32
Exploiting the Filtration Capacity of PSi Sensors: Detection in Whole Blood 34
Beyond the 1D PBG: Towards 2D PBG Sensors 34
Concluding Remarks 37
References 37
Resonant Waveguide Grating Biosensor for Microarrays 40
Introduction1 Introduction 41
Microarray Technologies2 Microarray technologies 42
DNA Microarrays2.1 DNA microarrays 43
Carbohydrate Microarrays2.2 Carbohydrate microarrays 43
Protein Microarrays2.3 Protein microarrays 44
Antibody Microarrays2.4 Antibody Microarrays 44
Membrane Protein Microarrays2.5 Membrane protein microarrays 44
Cellular Microarrays2.6 Cellular Microarrays 45
Microarray Fabrication2.7 Microarray fabrication 45
Microarray Assays and Detection2.8 Microarray assays and detection 45
Resonant Waveguide Grating Biosensor for Microarrays3 Resonant waveguide grating (RWG) biosensor for microarrays 46
RWG Biosensor3.1 RWG biosensor 47
RWG Imager3.2 RWG imagers 47
Label-Dependent Detection3.3 Label-dependent detection 48
Label-Independent Detection3.4 Label-independent detection 50
Concluding Remarks4 Concluding remarks 52
ReferencesReferences 52
Resonant Biochemical Sensors Based on Photonic Bandgap Waveguides and Fibers 56
Introduction 58
Detection Strategies for Absorption-Based Sensors 60
Sensing Using Hollow-Core Photonic Bandgap Fibers 62
Nonresonant Sensing 63
Resonant Sensing 65
Effect of Fiber Bending on Sensor Performance 68
Plasmon-Assisted Sensing Using PCFs 69
SPR Sensors Using Planar Photonic Bandgap Waveguides 72
SPR Sensors Using Photonic Bandgap Bragg Fibers 75
SPR Sensors Using Photonic Bandgap Honeycomb Fibers 78
Concluding Remarks 82
References 82
Nanophotonic and Subwavelength Structures for Sensing and Biosensing 86
Introduction 87
The Sensing Mechanism Based on Evanescent Waves 91
Sensors Based on Resonances in Diffraction Grating Structures 94
The GMR as a Sensor and Tunable Filter 98
Sensing Based on Localized Surface Plasmons and Surface Enhanced Effects 102
Nano-Enhancement of Surface Plasmon Sensitivity (LSPR Technique) 102
Resonant Raman Effect and Surface Enhanced Raman Scattering 105
Surface-Enhanced Fluorescence 108
Metallic Nanoapertures as Sensors 110
Photonic Crystals for Biosensing 112
Concluding Remarks and Future Directions 113
References 113
Part II Optical-Fiber Sensors 120
Fiber-Optic Chemical and Biosensors 121
Introduction 124
Transducers and Transduction Mechanisms 127
Absorption 127
Direct Absorption 128
Indirect Absorption 128
Fluorescence 131
Quenching 132
Energy Transfer 132
Lifetime 132
Raman Scattering 132
Surface Plasmon Resonance 133
Sensor Design 133
Extrinsic Sensors 135
Intrinsic Sensors 135
Core-Based Sensing Fibers 135
Evanescent Field Sensors 136
Modified Cladding Fibers 137
Case 1: Operations on the evanescent mode principles (ncl = nmcl < nco)
Case 2: Operations on the leaky mode principles (nmcl > nco>
Case 3: Operations on the partial leaky mode principles (ncl < nmcl <
Sensors Development and Processing 139
Selection and Characterization of Chemical Sensitive Materials 139
Polyaniline 139
Polypyrrole 140
Materials Characterization 140
Fiber Modification Process 143
Fiber Etching 143
Coating of Conducting Polymers 144
Sensor Characterization and Optimization 145
Sensing HCl and NH3 Vapors 146
Sensing Hydrazine Vapor 147
Sensing DMMP Vapors 148
Spatial Intensity Modulation for Sensor Applications 150
Fundamentals and Basic Theories 151
Development of Sensor Components 154
Application of SIM in Chemical Sensors 156
Total Intensity Measurements 156
Spatial Intensity Measurements 157
Concluding Remarks 159
References 159
Applications of Fiber Gratings in Chemical and Biochemical Sensing 162
Introduction 164
Fiber Bragg Gratings and Long-Period Gratings 165
Physical Principles and Characteristics 165
Straight and Tilted FBGs 165
Long-Period Gratings 169
Core-Cladding Intermodal Interferometers and Cascaded LPGs 170
Fabrication, Interrogation and Multiplexing Techniques 171
FBG Fabrication Techniques 171
Grating Sensor Interrogation Techniques 172
Multiplexing Techniques 172
Chemical and Biochemical Sensing Applications 172
Straight and Tilted FBG-Based Sensors 172
FBG-Based Transducers 172
Sensing Applications of Etched Straight FBGs 173
Sensing Applications of Tilted FBGs 174
Gold-Coated TFBGs and SPR Sensing Applications 174
LPG-Based Sensors 175
Bare LPGs as Chemo- and Biochemical Sensors 175
Overlayed and Coated LPGs for Improved Chemo- and Biochemical Sensing 177
Intermodal Interference-Based Sensors 183
Intermodal Interference in Photonic Crystal Fibers 183
Cascaded LPGs 183
Concluding Remarks 184
References 185
Hollow-Optical Fiber Probes for Biomedical Spectroscopy 188
Introduction 189
Design and Fabrication of Hollow-Optical Fibers 190
Fiber Probe for FT-IR SpectroscopyFT-IR spectroscopy 195
Hollow-Fiber Raman Probe 198
Concluding Remarks 202
References 203
Part III: Hollow-Waveguide and Micro-Resonator Sensors 204
Liquid-Core Waveguide Sensors 205
Introduction 207
Liquid-Core Waveguiding Principles 209
Total Internal Reflection-Based Waveguides 209
Liquid-Core Waveguides 210
Nanoporous Cladding Waveguides 211
Liquid-Liquid-Core Waveguides 211
Slot Waveguides 211
Non-TIR-Based Waveguides 212
Capillary ``Waveguide´´ 212
Metal-Clad Waveguides 214
Waveguides with Cladding Guiding 214
Fresnel Waveguides 215
Zero-Mode Waveguides 215
Interference-Based Waveguides 215
Bragg Fibers 216
Hollow-Core Photonic Crystal Fiber 217
2D Photonic Crystal-Waveguides 218
Antiresonant Reflecting Optical Waveguides 218
Sensor Applications 219
Absorption 219
Fluorescence 220
Scattering 222
Refractive Index Changes 223
Polarization Changes 225
Concluding Remarks 225
References 226
Capillary Waveguide Biosensor Platform 230
Introduction 232
Optical Design 233
Modal Concepts in Optical Waveguides 234
Leaky Optical Waveguides 238
Methods of Excitation 240
Direct Excitation 240
Evanescent Wave Excitation 241
Photon Emission from Fluorescent Molecules 242
Optimal Capillary for the Prototype CWBP 246
Optimizing Collection of Radiated Photons 248
Fiber Optic Receiver Efficiency 249
Practical Implementation of a CWBP 251
Detection Limit 252
The Capillary Waveguide Biosensor Platform 255
Results and Discussion 258
Precision and Accuracy 259
Hybridization 261
Synthetic Target Detection 262
Concluding Remarks 264
References 265
Label-Free Optical Ring Resonator Bio/Chemical Sensors 267
Introduction 269
Optical Ring Resonator Sensor Principles 270
Ring Resonator Configurations 273
Microsphere Ring Resonator 273
Planar Ring Resonator 273
Opto-Fluidic Ring Resonator 274
Ring Resonator Performance Comparison 275
Optical Ring-Resonant Bio/Chemical Sensing Applications 275
Ring Resonator Chemical Sensor 275
Heavy-Metal Detection 276
Chemical Vapor Detection 276
Pesticide Detection 277
Ring Resonator Biosensor 277
Biomolecule Receptors and Their Immobilization 278
Protein Detection 279
DNA Detection 280
Bacteria and Virus Detection 281
Concluding Remarks 283
References 283
Part IV: Terahertz Biosensing 288
Terahertz-Biosensing Technology: Progress, Limitations, and Future Outlook 289
Introduction 290
THz-Generation Principles 292
THz Biosensor Applications 293
THz Bioimaging 297
Comparison of THz Waves and Existing Optical Biosensors 298
Concluding Remarks 300
References 300