Composite membrane of graphene oxide and gold nanoparticles functionalized S fiber taper aptasensor for highly sensitive bisphenol A detection.

The S fiber taper (SFT) aptasensor with a composite sensitive membrane of graphene oxide and gold nanoparticles was proposed for the rapid and highly sensitive detection of bisphenol A (BPA). The SFT was obtained using a fusion splicer; subsequently, the composite film was deposited on its surface, and the specific aptamer was covalently bonded to the surface of gold nanoparticles. The detection mechanism relies on monitoring changes in the external refractive index induced by the specific binding of BPA to the aptamer. The developed SFT aptasensor exhibited a remarkable sensitivity of 15.5 nm/nM and a limit of detection as low as 0.01 nM for BPA. These findings highlight the aptasensor's potential for diverse monitoring applications.