Metal–organic frameworks: a novel SERS substrate

Abstract

We report the direct observation of surface‐enhanced Raman scattering (SERS) effect using metal–organic frameworks (MOFs) as substrates. Without the aid of any metal colloids or enhancing agents, the SERS signals of methyl orange (MO) adsorbed in MOFs were observed and even remained active if the organic linkers in MOFs were completely removed by high temperature and O2 plasma treatments. It implies that the SERS active site is at the metal oxide clusters. The ultraviolet‐visible spectra of MO, MOFs, and MO–MOF complexes show that absorption peaks are far from laser excitation line. Thus, conventional resonance enhancement effect should be ruled out, and charge‐transfer mechanism is the most likely scenario responsible for the observed SERS effect. Density functional theory (DFT) was used to interpret the chemical enhancement mechanism and the adsorption orientation‐dependent SERS spectra in our observation. The preferred adsorption orientations calculated by DFT method are consistent with the observed SERS results. Copyright © 2013 John Wiley & Sons, Ltd.

Plasmonic nanopatch array with integrated metal–organic framework for enhanced infrared absorption gas sensing

“…In recent years, hybrid plasmonic-MOF nanostructures have been reported to take the advantages of the strong gas adsorption capabilities of MOF materials and the optical field enhancement of plasmonics effect. These hybrid nanostructures have been applied in different applications, such as catalysis [15][16][17][18], imaging [19], surfaceenhanced Raman scattering [20][21][22][23][24][25][26][27] and surface-enhanced infrared absorption [9]. However, most of these reported hybrid plasmonic-MOF nanostructures are based on chemically synthesized metallic or semiconductor nanoparticles, which have several drawbacks.…”

Recent Advances in Metal Organic Frameworks Based Surface Enhanced Raman Scattering Substrates: Synthesis and Applications

“…SERS effect has been directly observed on some MOFs without the help of classic metal SERS substrates. For example, SERS effects of MIL-100(Al), MIL-100(Cr) and MIL-101(Cr) for methyl orange have been reported by Tsung-Han Yu et al [ 38 ]. The SERS effect was ascribed to the charge transfer effect between the metal clusters in MOFs and the absorbed methyl orange molecules.…”

“…It should be noted that some MOFs can contribute extra SERS enhancement and could be used as SERS substrates independently. SERS enhancement effects of MOFs have been first observed on MIL-100 (Al), MIL-100 (Cr), and MIL-101 (Cr) without the help of any other enhancing material [ 38 ]. The SERS effect of MOFs was mainly due to the charge transfer effect between the adsorbed molecules and metal oxide clusters in MOFs.…”

SERS-active MIL-100(Fe) sensor for sensitive detection of organic dyes and its enhancement mechanism study

“…2013年, Lee课题组 [11] 发现MIL-101(Cr)、MIL-100(Cr) [17] . 由图3(a)可以看出, MO的检测 (Fe)自身的CE增强机制 [18] 共同放大甲基橙的检测信号.…”