Monitoring Solid‐Phase Reactions in Self‐Assembled Monolayers by Surface‐Enhanced Raman Spectroscopy

Abstract

Nanopatterned surfaces enhance incident electromagnetic radiation and therebye nable the detection and characterization of self-assembled monolayers (SAMs), for instance in surface-enhanced Raman spectroscopy( SERS). Herein, Au nanohole arrays,d eveloped and characterized as SERS substrates,are exemplarily used for monitoring as olidphase deprotection and as ubsequent copper(I)-catalyzed azide-alkyne cycloaddition "click"reaction, performed directly on the corresponding SAMs.The SERS substrate was found to be highly reliable in terms of signal reproducibility and chemical stability.F urthermore,t he intermediates and the product of the solid-phase synthesis were identified by SERS. The spectra of the immobilized compounds showed minor differences compared to spectra of the microcrystalline solids. With its uniform SERS signals and the high chemical stability, the platform paves the way for monitoring molecular manipulations in surface functionalization applications.

Controlling Polymorphic Transitions in n-Type Organic Semiconductor Single Crystals by Alkyl Chain Engineering

“…This confirms 28 The two peaks at 1025 and 1063 cm −1 were assigned to C−C stretching of the trans ν(C−C) T and gauche ν(C−C) G conformers in the alkyl chains (Figure 6a, pink and green). These peaks have been well studied in alkane molecules, 45,47,48 and the intensity ratio between these peaks indicates dynamic disorder where a ratio of 1 represents freely moving and rotating chains in a disordered state. The II−III transition also exhibits a quinoidal-to-aromatic transition within the conjugated core, stabilizing a biradical ground state, 28 which is represented by the peaks at 1387 and 1442 cm −1 .…”

Rational Design of Surface‐Enhanced Raman Scattering Substrate for Highly Reproducible Analysis

“…[32][33] For example, nanopore arrays were fabricated on single-crystal Si substrates using a two-layer electron beam lithography process, exhibiting high reliability in terms of signal reproducibility and chemical stability. [34] The nanopatterned substrates had the character of ultra-high sensitivity due to the pattern enhanced the incident electromagnetic radiation to increase the intensity of the scattered light (Figure 2A). This kind of material can be used to detect solid-phase reactions, such as the "click" reaction of copper(I) catalyzed azide acetylene cycloaddition (CuAAC), to track the evolution of various molecular model systems under chemical modification to describe species-specific vibrational modes.…”

Two‐Dimensional Polymer Networks Locking on Inorganic Nanoparticles

“…The surfaces of inorganic nanoparticles play a critical roles for many applications, such as catalysis, [1–6] chemical sensing, [7–11] and surface enhanced Raman/fluorescence spectroscopy [12–19] . Such applications require the balance between surface accessibility of reactant/probe/target molecules and the colloidal stability of NPs [20–25] .…”