Aptamer-modified anodized aluminum oxide-based capacitive sensor for the detection of bisphenol A

We describe a rapid, sensitive, and low-cost method to detect bisphenol A (BPA) using an anodized aluminum oxide-based capacitive sensor. BPA is detected by measuring the change in capacitance caused by the biospecific binding of BPA with a BPA aptamer that is immobilized on the electrode surface. For a solution containing 100 pM BPA, the capacitance decreased by approximately 3%. In addition, we fabricated a capacitive sensor array and demonstrated that BPA in environmental samples can be measured using our capacitive sensor. (C) 2011 American Institute of Physics. [doi:10.1063/1.3555345]