Highly sensitive and selective optofluidics-based immunosensor for rapid assessment of Bisphenol A leaching risk.

Bisphenol A (BPA), a xenoestrogenic endocrine-disrupting chemical, is used in many consumer products worldwide and is widely detected in the environment and in food. Combining the advantages of evanescent wave fiber optic sensor and microfluidic technology, an all-fiber optofluidics-based bioassay platform (AFOB) was developed for the rapid immunoassay and assessment of BPA. The captured molecular BPA-bovine serum albumin was covalently immobilized on the surface of the fiber optic sensor. A mixture of different concentrations of BPA and a certain concentration of fluorescence-labeled anti-BPA monoclonal antibodies after pre-reaction was introduced to the optofluidic cell. A higher concentration of BPA reduced the fluorescence-labeled antibodies bound to the sensor surface and thus reduced fluorescence signals. Under optimal conditions, the BPA quantified as 0.5-100 μg/L, with a detection limit of 0.06 μg/L. The high selectivity of the sensor was evaluated in terms of its response to several potentially interfering chemicals. The potential interference of an environmental sample matrix was assessed by spiked samples, and the recovery of BPA ranged from 90% to 120% with relative standard deviation values of <9.1%. The AFOB and high-performance liquid chromatography had a desired correlation (R(2)=0.9958). The sensing platform was successfully used to assess BPA leaching from polycarbonate bottles at 45 °C and 80 °C, indicating that more BPA was substantially leached at elevated temperature and extend time. Thus, the developed sensing strategy can be an alternative method to rapidly analyze and assess the migration mechanism and fate of BPA or other pollutants.