Ultra-low-power neurotransmitter sensor using novel "click" chemistry aptamer-functionalized deep subthreshold Schottky barrier IGZO TFT

This report implements for the first time an alkyne-azide "click" chemistry to position dopamine-specific aptamer receptors on InGaZnO (IGZO) thin film transistor (TFT) surfaces for sensitive and selective detection of dopamine. It incorporates catalytic attachment of an alkyne-terminated silane to an azide-anchored aptamer that precludes the need of an intermediate molecular cross-linking bond. The TFTs demonstrate high-gain (similar to 1000) Schottky action in deep subthreshold regime achieved through high-quality metal-semiconductor contact engineering which enables almost unity voltage operation. The aptamer is specifically synthesized for selectivity towards dopamine and volt-order-calibrated responses with empirical and theoretical detection limits of 1 nM and 100 pM are achieved.