Enzyme-coated single ZnO nanowire FET biosensor for detection of uric acid

Qualitative and quantitative detection of biological and chemical species is crucial in many areas, ranging from clinical diagnosis to homeland security. Due to the advantages of ultralow detection limit, label-free, fast readout and easy fabrication over the traditional detection systems, semiconductor nanowire based electronic devices have emerged as a potential platform. In this paper, we fabricated a single ZnO nanowire-based biologically sensitive field-effect transistors (bioFETs) for detection of different concentrations of uric acid solution at the same time. The addition of uric acid with the concentrations from 1 pM to 0.5 mM resulted in the electrical conductance changes of up to 227 nS, and the response time turns out to be in the order of millisecond. The ZnO NW biosensor could easily detect as low as 1 pM of the uric acid with 14.7 nS of conductance increase, which implied that the detection limit of the biosensor can be as low as 1 pM.