Principles of Surface-Enhanced Raman Spectroscopy

Preface Notations, units and other conventions 1 A quick overview of SERS 1.1 What is SERS? - Basic principles 1.2 SERS probes and SERS substrates 1.2.1 SERS substrates 1.2.2 SERS probes 1.2.3 Example 1.3 Other important aspects of SERS 1.3.1 SERS enhancements 1.3.2 Sample preparation and metal/probe interaction 1.3.3 Main characteristics of the SERS signals 1.3.4 Related techniques 1.3.5 Related areas 1.4 Applications of SERS 1.4.1 Raman with improved sensitivity 1.4.2 SERS vs. fluorescence spectroscopy 1.4.3 Applications specific to SERS 1.5 The current status of SERS 1.5.1 Brief history of SERS 1.5.2 Where is SERS now? 1.5.3 Current “hot topics” 1.6 Overview of the book content 1.6.1 General outline of the book 1.6.2 General “spirit” of the book 1.6.3 Different reading plans 2 Raman spectroscopy and related techniques 2.1 A brief introduction 2.1.1 The discovery of the Raman effect 2.1.2 Some applications of Raman spectroscopy 2.1.3 Raman spectroscopy instrumentation 2.2 Optical spectroscopy of molecules 2.2.1 The energy levels of molecules 2.2.2 Spectroscopic units and conversions 2.2.3 Optical absorption 2.2.4 Emission and luminescence 2.2.5 Scattering processes 2.2.6 The concept of cross-section 2.2.7 The Raman cross-sections 2.2.8 Examples of Raman cross-sections 2.2.9 Mechanical analogs 2.3 Absorption and fluorescence spectroscopy 2.3.1 Optical absorption and UV/Vis spectroscopy 2.3.2 Fluorescence spectroscopy 2.3.3 Photo-bleaching 2.4 Phenomenological approach to Raman 2.4.1 Dipolar emission in vacuum 2.4.2 The concepts of polarizability and induced dipole 2.4.3 The linear optical polarizability 2.4.4 The Raman polarizability 2.4.5 The local field correction 2.4.6 Polarizabilities and scattering cross-sections 2.4.7 Final Remarks on the phenomenological description 2.5 Vibrations and the Raman tensor 2.5.1 General considerations 2.5.2 A primer on vibrational analysis 2.5.3 The Raman tensor 2.5.4 Link to the Raman polarizability 2.5.5 Limitations of the classical approach 2.5.6 A brief overview of related Raman scattering processes 2.6 Quantum approach to Raman scattering 2.6.1 Justification of the classical approach 2.6.2 The quantization of vibrations 2.6.3 The full expressions for the Raman cross-section 2.6.4 The anti-Stokes to Stokes ratio 2.7 Advanced aspects of vibrations in molecules 2.7.1 More on vibrational analysis 2.7.2 More on symmetries and Raman selection rules 2.7.3 Modeling of molecular structure and vibrations 2.8 Summary 3 Introduction to plasmons and plasmonics 3.1 Plasmonics and SERS 3.2 The optical properties of noble metals 3.2.1 The Drude model of the optical response 3.2.2 The optical properties of real metals 3.2.3 Non-local optical properties 3.2.4 What makes the metal-light interaction so special? 3.3 What are plasmons? 3.3.1 The plasmon confusion 3.3.2 Definition and history 3.3.3 The relation between plasmons and the dielectric function 3.3.4 Electromagnetic modes in infinite systems 3.3.5 Electromagnetic modes of a system of material bodies 3.3.6 Classification of electromagnetic modes 3.3.7 Other properties of electromagnetic modes 3.3.8 Summary and discussion 3.4 Surface plasmon-polaritons for planes 3.4.1 Electromagnetic modes for a planar dielectric/metal interface 3.4.2 Properties of the SPP modes at planar metal/dielectric interfaces 3.4.3 Coupling of PSPP modes with light 3.4.4 PSPP resonances at planar interfaces 3.4.5 Local field enhancements and SPPs at planar interfaces 3.4.6 SPP modes on planar interfaces: a brief summary 3.5 Localized surface plasmon-polaritons 3.5.1 Introduction to localized SPPs 3.5.2 LSP on planar structures 3.5.3 LSP modes of a metallic sphere 3.5.4 LSP modes of nano-particles 3.5.5 LSP Resonances 3.5.6 Local field enhancements and LSP 3.5.7 Interaction of SPPs - gap SPPs 3.6 Brief survey of plasmonics applications 3.6.1 Applications of surface plasmon resonances 3.6.2 SPP propagation and SPP optics 3.6.3 Local field enhancements 4 SERS enhancement factors 4.1 Definition of the SERS enhancement factors 4.1.1 General considerations 4.1.2 The analytical point of view 4.1.3 The SERS substrate enhancement factor - Experimental approach 4.1.4 The SERS cross-section and single molecule EF 4.1.5 The SERS substrate enhancement factor - Formal definition 4.1.6 Discussion and merits of the various definitions 4.2 Experimental measurement of SERS EFs 4.2.1 The importance of the non-SERS cross-section 4.2.2 Example of AEF measurements 4.2.3 Link between SSEF definition and experiments 4.3 Overview of the main EM effects in SERS 4.3.1 Analysis of the EM-problem of SERS 4.3.2 Local field enhancement 4.3.3 Radiation enhancement 4.3.4 Other EM effects 4.3.5 The common