One-pot rapid and ultrasensitive sensing strategy for endocrine disruptor bisphenol A using cationic AuNPs and aptamer

Abstract

A novel Cys-Lys-Arg-Lys-Arg-Lys-Arg peptide-capped cationic gold nanoparticles were synthesized by the utilization of microwave irradiation. The prepared gold nanoparticles along with bisphenol A aptamer have been employed for the development of a colorimetric aptasensor for bisphenol A based on the electrostatic interactions among them and the specific recognizing ability of aptamer. The presence of bisphenol A initiated the formation of bisphenol A-aptamer complex, thus added gold nanoparticles remain stable in the reaction mixture, and corresponding to this very less charge occurs into the surface plasmon resonance peak. Depending on the concentration of bisphenol A, a particular amount of free aptamer was present in the reaction which causes the aggregation of gold nanoparticles, and corresponding to this bisphenol A was detected. Under the optimized conditions, bisphenol A concentrations from 200 to 1000 pM exhibited a good linear correlation (R2 = 0.99581) with a detection limit of 87.04 pM in 7 min. The aptameric ability was studied by replacing the bisphenol A with its other analogues such as bisphenol B, bisphenol F, phenol, and benzophenone, and also in the mixture of all these. The obtained results have shown that the developed aptasensor exhibited five-fold selectivity towards bisphenol A as compared to its other analogues. Utilization of the proposed aptasensor was carried out in mineral water, tap water, and packed juice where the percentage recovery was found from 96.61 to 101.23. Thus, the developed colorimetric aptasensor exhibits excellent advantages of rapidity, simplicity, cost-effectiveness, high selectivity, and sensitivity for bisphenol A.