Studies On The Fabrication And Applications Of Film Reference Electrode On Microfluidic Chips

In microfluidic systems analytes are separated in microchannels and then detected by detection systems. Thus the overall performance of the detection system can affect such factors of the whole system as the detection limits, separation efficiency, detection range, sample volume etc, making it a key part of the microfluidic system. Among all the detection techniques, electroanalytical techniques are advantageous, and there are many reports on its integration onto micochips. But the miniaturization of the electroanalytical system has often been restricted to the working electrode, and in many cases a commercial macroscopic reference electrode has been used. Although reference electrodes are an essential component, their importance seems to be frequently ignored and only a few papers have been devoted to miniature reference electrode and fabrication process reported are comparatively complicated. This paper reports on the integration of planar reference electrode onto glass substrate through a combination of electroless deposition and electroplating. The stability and performance of the integrated reference electrode are discussed.In chapter 1, studies on microfluidic electrochemical systems are classified and summarized. Its development trend as well as problems existent is discussed.In chapter 2, studies on the fabrication of microelectrodes are elaborated, which include different working electrodes materials, main fabrication processes and their advantages. Problems existent in reference electrode studies are discussed.In chapter 3, process of the integration of planar reference electrode is described. Factors influencing electroless deposition and electroplating are discussed and optimized.In chapter 4, stability tests as well as performance experiments are discussed, which show the short-term and long-term stability of the planar reference electrode and that it can provide a stable reference in solutions where concentration of Cl" keeps invariable. Performance of the planar reference electrode is compared with that of macroscopic commercial reference electrode, which proves the good performance of the planar reference electrode as well as the feasibility of the fabrication process.In chapter 5, the fabrication process of the film Ag/AgCl electrode as well as its application is summarized. Prospect of its development are described.