An upconversion biosensor based on DNA hybridization and DNA-templated silver nanoclusters for the determination of acrylamide

Acrylamide is widely present in many fried and baked foods, that has been proved as potentially carcinogenic to humans. In this work, a novel biosensor using core-shell upconversion nanoparticles (CSUCNPs) with aptamer as recognized element was designed for the determination of acrylamide. The principle of this work was based on the fluorescence resonance energy transfer (FRET) process from CSUCNPs to silver nanoclusters (AgNCs). Whereas the binding between acrylamide and the aptamer disturbed the DNA structure and inhibited the synthesis of AgNCs, which induced a higher fluorescence intensity. Under the optimal conditions, a low limit of detection (LOD) was calculated as 1.13 nM in the range of 1–105 nM. This biosensor was further applied in the spiked food samples to validate the applicability that recoveries were at the range of 78.52–117.09% with a relative standard deviation of 1.54–10.46%. The approach was compared with the standard HPLC method in great agreement (P > 0.05).