Polyaniline-graphene based α-amylase biosensor with a linear dynamic range in excess of 6 orders of magnitude

We have developed a highly sensitive α-amylase immunosensor platform, produced via in situ electropolymerization of aniline onto a screen-printed graphene support (SPE). Covalently binding an α-amylase specific antibody to a polyaniline (PANI) layer and controlling device assembly using electrochemical impedance spectroscopy (EIS), we have achieved a highly linear response against α-amylase concentration. Each stage of the assembly was characterized using a suite of high-resolution topographical, chemical and mechanical techniques. Quantitative, highly sensitive detection was demonstrated using an artificially spiked human blood plasma samples. The device has a remarkably wide limit of quantification (0.025-1000 IU/L) compared to α-amylase assays in current clinical use. With potential for simple scale up to volume manufacturing though standard semiconductor production techniques and subsequently clinical application, this biosensor will enable clinical benefit through early disease detection, and better informed administration of correct therapeutic dose of drugs used to treat α-amylase related diseases.