Controlled stepwise-synthesis of core–shell Au@MIL-100 (Fe) nanoparticles for sensitive surface-enhanced Raman scattering detection

Abstract

A novel porous Au@MIL-100 (Fe) core-shell structure in which a Au nanoparticle (AuNP) core is coated with a controllable uniform metal-organic framework shell has been fabricated by using a facile step-by-step procedure. The as-synthesized Au@MIL-100 (Fe) takes advantage of the high adsorption capability of the MIL-100 (Fe) shell and the localized surface plasmon resonance properties of the AuNP core, and was used as a hybrid surface enhanced Raman scattering (SERS) substrate. We discussed the fabrication, physical characterization, and SERS activity of our novel substrate, and found that this new substrate had controllable shell thickness, high stability and good SERS activity. The potential practical application of the novel SERS substrate was firstly evaluated by quantitative analysis of malachite green in aquaculture water. The method showed good linearity between 3.0 × 10(-8)-1.0 × 10(-6) mol L(-1) for malachite green with a correlation coefficient of 0.9945. The limit of detection (LOD) was 8.0 × 10(-9) mol L(-1). Then the applicability of Au@MIL-100 (Fe) as the SERS substrate for in situ detection of malachite green on the fish body indicated its great potential as a rapid and on-site detection analytical strategy. In addition, the preliminary investigation also shows that the Au@MIL-100 (Fe) has SERS activity toward carbon disulfide which would be a new strategy for SERS-based gas sensors.

{Nano‐gold, iron(III)‐1,3,5‐benzene tricarboxylate metal organic framework (MOF)} nano‐composite as precursor for laser ablation generation of gold‐iron AumFen+/− (m = 1–35, n = 1–5) clusters. Mass spectrometric study

“…Metal organic frameworks (MOFs) are a group of crystalline porous materials with several unique properties such as large Brunauer–Emmett–Teller (BET) surface areas (200–6000 m 2 g −1 ), high porosity, pore volume (0.2–3 cm 3 g −1 ), and various pore sizes (2–50 Å) . Their properties make them excellent materials for selective gas storage and separation, catalysis, various biomedical applications (drug storage and delivery), enhanced catalytic performance, and use for sensitive surface‐enhanced Raman scattering detection, for example . The field of MOFs study is rapidly evolving with a new trend to combine the high adsorption properties of MOFs and the catalytic activity of metallic nanoparticles (MNPs) …”

“…Their properties make them excellent materials for selective gas storage and separation, catalysis, various biomedical applications (drug storage and delivery), enhanced catalytic performance, and use for sensitive surface‐enhanced Raman scattering detection, for example . The field of MOFs study is rapidly evolving with a new trend to combine the high adsorption properties of MOFs and the catalytic activity of metallic nanoparticles (MNPs) …”

“…High interest has also been shown in gold nanoparticles (AuNPs) which are a suitable material in many biomedical applications . AuNPs have a high surface energy which causes the nanoparticles to tend to aggregate, so making them unstable for long storage times . The aggregation of the core of AuNPs can be dramatically limited by adsorption on the surface of the MOFs and the production of core shell structures by post‐synthetic metalation .…”

“…The aggregation of the core of AuNPs can be dramatically limited by adsorption on the surface of the MOFs and the production of core shell structures by post‐synthetic metalation . The composite {AuNPs, MOFs}, which combines high adsorption capability (MOFs) with good catalytic properties (AuNPs), is stable under various reaction conditions and displays even higher catalytic activity than AuNPs …”

Analysis of forchlorfenuron and thidiazuron in fruits and vegetables by surface‐enhanced Raman spectroscopy after selective solid‐phase extraction with modified β‐cyclodextrin

“…Owing to its high sensitivity, short response time, and relatively simple operation, surface‐enhanced Raman spectroscopy (SERS) has received increasing attention for the detection of food additive , pesticide residues , drug residues , and so forth . Although the LODs of these methods were acceptable, their further application to detect specific analytes in complex matrices, especially for the quantitative analysis of trace analytes, were greatly limited by the serious matrix interferences and poor selectivity.…”