Biosensors of ZnO nanotetrapods and HEMT for detecting uric acid

A new prototype of Uric Acid (UA) biosensor is constructed by combining high electron mobility transistors (HEMTs) with Zinc Oxide Nanotetrapods (T-ZnOs). T-ZnOs are synthesized by chemical vapor deposition (CVD). These T-ZnOs with high specific areas are evenly distributed on the gate areas of HEMTs to improve the sensitivity of the HEMTs. Uricase is then immobilized on the T-ZnOs by their different isoelectric points (IEP). When different UA solutions are added to the gate areas of HEMTs, the biosensors respond in around one second through signal current change. The fabricated biosensors can detect target UA in solutions of concentrations ranging from 0.2 nM to 0.2 mM with a detection limit of 0.2 nM.