Highly Sophisticated Electrochemical Analysis System with an Integrated Microfluidic System Based on Electrowetting

An integrated device which can conduct timely transport of a sample solution and analyze its components was constructed. The transport of solutions was based on capillary action on hydrophilic glass areas and the control by valves which operate based on electrowetting. Electrochemical sensors including glucose, lactate, GOT, GPT, pH, ammonia, urea, and creatinine were integrated. Sensors for the former four are amperometric whereas the detection of the latter four are based on potentiometry. The ammonia, urea, and creatinine sensors had an air gap structure to realize a fast response. The sensors for GOT and GPT had a freeze-dried substrate matrix to realize rapid mixing. The sample solution was transported to required sensing sites at desired times. The integrated sensors showed distinct responses upon the introduction of a sample solution. Linear relationships were observed between the output signals and the concentration or the logarithm of the concentration of the analytes.