To date, there are few reports regarding the development of RNA aptamer-based biosensors for the detection of small molecules. The possible reason is attributed to the weak nuclease resistance of RNA in biological environments. In this study, we have developed an RNA aptamer-based gold nanoparticle (AuNP) sensor for fluorometric detection of Neomycin B in milk. This aptasensor depends on the self-assembly of the RNA aptamer/Neomycin B complex and fluorescence quenching by AuNPs. This biosensor exhibited a low detection limit of 0.01 μM, with a linear dynamic range from 0.1 to 10 μM in milk, and a good selectivity toward Neomycin B. Specifically, because of the shorter RNA fragments and the nuclease inhibition ability of the RNA-modified AuNPs, the RNA sequences remained stable during the experiments. This work will serve as an example for the development of novel biosensors based on RNA aptamers. Graphical Abstract An RNA aptamer-based nanoparticle sensor, developed for the detection of Neomycin B in milk, shows high binding affinity and selectivity. This aptasensor depends on the self-assembly of the aptamer/ligand complex and fluorescence quenching by gold nanoparticles (AuNPs). Because of the shorter RNA fragments and the nuclease inhibition ability of RNA-modified AuNPs, RNA sequences remain stable during the detection.
Keywords: Aptasensor; Gold nanoparticle; Neomycin B; RNA aptamer; Self-assembly.