Silica-Coated Silver Nanoparticles Decorated with Fluorescent CdTe Quantum Dots and DNA Aptamers for Detection of Tetracycline

Abstract

An aptamer-labelled fluorescent nanoprobe-integrated shell-isolated nanoparticle-enhanced fluorescence spectroscopy (SHINEFs) had been proposed for selective and sensitive detection of Tc. In the study, CdTe quantum dots were used as a fluorescent source; silica-coated silver nanoparticles (Ag@SiO2) were used as the SHINEFs material for signal amplification. The maximum SHINEFs was obtained with a 9 nm silica spacer. The linear range of the nanoprobe was from 0.2 to 400 μM, and the detection limit was 16.2 nM. Furthermore, our synthesized nanoprobe was applied to detect Tc in milk with a recovery rate of 96.50–101.80%. These results showed that the as-prepared nanoprobe was a rapid detection tool for Tc with high sensitivity and selectivity. The aptamer-modified nanoprobe can also be applied to the analysis of other substances by altering the aptamer.