A Label-Free Impedimetric Immunosensor Based on Humidity Sensing Properties of Barium Strontium Titanate

Abstract

A novel signal amplification mechanism for impedimetric biosensors is proposed. The proposed mechanism is based on humidity sensing properties of BST composite film and eliminates the need for application of bioactive labels for signal enhancement in amplified impedimetric biosensors. It suggests a good alternative to conventional impedimetric biosensors by improving the detection limit without adding any extra complexity to the system. It is direct and label-free, and can be employed for detection of a wide range of analytes. The sensing capability of the system was exemplified for detection of anti-BSA protein and a low detection limit of 10 ng/ml was obtained. © International Federation of Medical and Biological Engineering 2009.