pH-based potentiometrical flow injection biosensor for urea

In this study, the pH-based urea biosensor has been used in the flow injection analysis (FIA) system. A type of potentiometric sensing system for urea was constructed, which based on the buffer concentration to the response of urea. However, the extended-gate field effect transistor is applied to fabricate the pH-based urea biosensor and the photo-curable gels (PVA-SbQ) is used to immobilize the urease. In aspect of the flow injection analysis system, the samples were injected by the pumps and passed through from the injection valve, which could be single port or multi-ports. And then, the solvent and the samples were mixed. After that, the solution of mixer flows to micro flow through cell. Through the flow system, the output signal is observed by the detection. ow injection analysis system has some advantages, such as reaction faster, more reproducible, long lifetime and less work-consuming. Hence, the application of the flow injection analysis system can improve the analytical feature of the urea biosensor.