Label-Free Aptamer-Based Biosensor for Specific Detection ofChloramphenicol Using AIE Probe and Graphene Oxide

摘要

A facile, sensitive, and label-free aptamer-basedfluorescent biosensor (aptasensor) for chloramphenicol(CAP) detection was successfully developed based on anaggregation-induced emission (AIE) probe and grapheneoxide (GO). In this aptasensor, the specific aptamer of CAP(C-Apt) is used as the recognition part, an AIE molecule,9,10-distyrylanthracene (DSA) derivative with short alkylchains (9,10-bis{4-[2-(N,N,N-trimethylammonium)-ethoxy]-styrene}anthracene dibromide, DSAC2N), as the fluorescentprobe, and GO with a low oxidation degree as the fluorescentquencher. Initially, the AIE probe DSAC2N and C-Apt couldbe adsorbed on GO through π-stacking interactions, and the fluorescence of DSAC2N could be efficiently quenched due to theenergy transfer between DSAC2N and GO. When CAP is added, C-Apt can preferentially bind with CAP and the newly formedcomplex (C-Apt?CAP) can be released from GO, resulting in the recovery of the fluorescence signal of DSAC2N. Thus, withthe aid of GO, turn-on detection of CAP can be readily realized by monitoring the fluorescence signal of DSAC2N from “off” to“on”. Under the optimized conditions, the aptasensor exhibits a high sensitivity toward CAP with a limit of detection of 1.26pg/mL. Besides, we have successfully applied this aptasensor to the detection of CAP in spiked milk.