Fabrication of Gold Nanoparticle-Embedded Metal–Organic Framework for Highly Sensitive Surface-Enhanced Raman Scattering Detection

Abstract

Surface-enhanced Raman scattering (SERS) signals strongly rely on the interactions and distance between analyte molecules and metallic nanostructures. In this work, the use of a gold nanoparticle (AuNP)-embedded metal-organic framework was introduced for the highly sensitive SERS detection. The AuNPs were in situ grown and encapsulated within the host matrix of MIL-101 by a solution impregnation strategy. The as-synthesized AuNPs/MIL-101 nanocomposites combined the localized surface plasmon resonance properties of the gold nanoparticles and the high adsorption capability of metal-organic framework, making them highly sensitive SERS substrates by effectively preconcentrating analytes in close proximity to the electromagnetic fields at the SERS-active metal surface. We discussed the fabrication, physical characterization, and SERS activity of our novel substrates by measuring the Raman signals of a variety of model analytes. The SERS substrate was found to be highly sensitive, robust, and amiable to several different target analytes. A SERS detection limit of 41.75 and 0.54 fmol for Rhodamine 6G and benzadine, respectively, was demonstrated. The substrate also showed high stability and reproducibility, as well as molecular sieving effect thanks to the protective shell of the metal-organic framework. Subsequently, the potential practical application of the novel SERS substrate was evaluated by quantitative analysis of organic pollutant p-phenylenediamine in environmental water and tumor marker alpha-fetoprotein in human serum. The method showed good linearity between 1.0 and 100.0 ng/mL for p-phenylenediamine and 1.0-130.0 ng/mL for alpha-fetoprotein with the correlation coefficients of 0.9950 and -0.9938, respectively. The recoveries ranged from 80.5% to 114.7% for p-phenylenediamine in environmental water and 79.3% to 107.3% for alpha-fetoprotein in human serum. These results foresee promising application of the novel metal-organic framework based composites as sensitive SERS-active substrates in both environmental and clinical samples.

Ultrasonic synthesis of highly dispersed Au nanoparticles supported on Ti-based metal–organic frameworks for electrocatalytic oxidation of hydrazine

“…28 Compared to pure NH 2 -MIL-125(Ti), Pt/NH 2 -MIL-125(Ti) showed an enhanced photocatalytic activity toward CO 2 reduction, whereas Au has a negative effect on this reaction. 30 Tang's group synthesized interesting core-shell structured Au@MOF-5 NPs 31 and Pd @IRMOF-3 32 composites for SERS sensing of CO 2 and the catalysis of cascade reaction, respectively. 29 Au NPs/MIL composites were also prepared through a encapsulation strategy and employed to catalyze the reduction of 4nitrophenol, and possessed better catalytic activity than pure Au NPs.…”

Gold nanoparticles and polyethylene glycols functionalized conducting polyaniline nanowires for ultrasensitive and low fouling immunosensing of alpha-fetoprotein

“…4B) with a limit of detection (LOD) of 0.007 pg mL À 1 (3s, n¼10). The LOD is much lower than that achieved by previously reported AFP immunosensors, such as those using localized surface plasmon resonance (LSPR) based on gold nano-mushroom (Li et al, 2015b), surface-enhanced Raman scattering (SERS) based on gold nanoparticle-embedded metal-organic framework (Hu et al, 2014), and enzyme-linked immunosorbent assay (ELISA) based on molecularly imprinted polymers (MIPs) (Bi and Liu, 2014). This low LOD was mainly attributed to the good electron transfer capability of AuNPs/PANI and the excellent biocompatibility of PEG, which can provide a suitable micro-environment for the immobilized AFP antibody to exhibit better binding affinity.…”

Synthesis and characterization of high-purity gold nanoparticles by laser ablation method using low-energy Nd:YAG laser 1064 nm

“…One of the NPs intensively studied was gold nanoparticles (GNPs) [1][2][3]. GNPs have become a great interest for many scientists to be applied in various fields as catalysis [4], surface-enhanced Raman scattering [5], photonics device [6], electrochemical sensors [7], and medical applications [8]. In the medical field, GNPs were applied as drug carriers, contrast agents, thermal therapy, and radiosensitisers due to its peculiar characteristics compared to the bulk material including electronic, optic, and chemical properties [9,10].…”