Spectroscopic ellipsometry-based aptasensor platform for bisphenol a detection

Endocrine-disrupting chemicals (EDC) are pollutants that alter the function of the endocrine system by interfering with hormone biosynthesis, metabolism, or action. In this study, a spectroscopic ellipsometry platform is proposed using aptamers for the sensitive and selective detection of an EDC, 2,2-Bis(4-hydroxyphenyl)propane (Bisphenol A, BPA). Two different BPA-specific aptamers (Anti-BPA1 and Anti-BPA2) were immobilized to silicon wafer chips by the layer-by-layer self-assembly, a detection limit of 215 pM and 36 pM was obtained using the ellipsometric method for Anti-BPA1 and Anti-BPA2, respectively. Sensor specificity was tested with 2,2-Bis(4-hydroxyphenyl)butane and a maximum RSD of 3.8% was obtained. It has been reported that both aptasensors based on spectroscopic ellipsometry exhibit adequate analytical performance.