An aptamer sensor based on AgNPs@MOF for surface-enhanced Raman spectroscopy detection of sulfadimethoxine in food.

A highly sensitive aptamer sensor (aptasensor) is proposed based on metal-organic frameworks-silver nanoparticles (AgNPs@MOF) to detect sulfadimethoxine (SDM) by surface-enhanced Raman spectroscopy (SERS). AgNPs@MOF with SERS activity was successfully fabricated by synthesizing AgNPs in situ on the surface of MIL-101(Fe), and SDM aptamer and Raman reporter 4-aminophenthiophenol (4-ATP) were selected as specific recognition elements and signal probes, respectively. When SDM was absent, the SDM aptamers were effectively adsorbed on the surface of AgNPs@MOF, thus keeping AgNPs@MOF in a dispersed state, resulting in a weakened SERS signal of 4-ATP.

Ag-carbon dots with peroxidase-like activity for colorimetric and SERS dual mode detection of glucose and glutathione.

Currently, nanozymes have made important research progress in the fields of catalysis, biosensing and tumor therapy, but most of nanozymes sensing systems are single-mode detection, which are easily affected by environment and operation, so it is crucial to construct nanozymes sensing system with dual-signal detection to obtain a more stable and reliable performance. In this paper, Ag-carbon dots (Ag-CDs) bifunctional nanomaterials were synthesized using carbon dots as reducing agent and protective agent by a facile and green one-step method. A simple and sensitive colorimetric-SERS dual-mode sensing platform was constructed for the detection of glucose and glutathione(GSH) in body fluids by taking advantage of good peroxidase-like and SERS activities of Ag-CDs.

An aptamer-based colorimetric/SERS dual-mode sensing strategy for the detection of sulfadimethoxine residues in animal-derived foods.

Residues of sulfadimethoxine (SDM) in animal-derived foods have attracted widespread public concern. Herein, we propose an aptamer-based colorimetric/SERS dual-mode sensing strategy for the determination of SDM based on hexadecyl trimethyl ammonium bromide (CTAB) induced aggregation of nanoparticles. In the absence of SDM, the SDM aptamer formed a supramolecular composite with CTAB, and the 4-mercaptopyrimidine functionalized gold nanoparticles (AuNPs@4-MPY) remained dispersed due to the lack of CTAB.