Study On Micro Electrode Array Based Electroluminescent Oxygen Sensor

Miniaturization of analytical instrument is quite a hot issue of the research in thisfield. Although the conventional optical sensors often utilize photoluminescence asoutput signal which is basically rely on an external excitation light source, and thatwould hamper further miniaturization of the corresponding sensor devices. Therefore,the study of how to achieving higher integration level in optical sensor devices isalways an important topic.In this paper, we designed and fabricated a new type of gas sensor based onelectroluminescent microelectrodes. The light-emitting/sensing material of the sensorcan be drop cast on the surface of the comb-shaped microelectrode, which achievesmuch higher surface-to-volume ratios and therefore improves the response speed to thegas molecules. The electroluminescence capability of varies fluorescent andphosphorescent materials such as poly(N-vinylcarbazole): Pt(II) octaethylporphine,Tris(2,2′-bipyridine)ruthenium(Ⅱ)[Ru(bpy)32+], have been estimated respectively. Wehave optimized the processes of devices preparation, then studied the synthesis,electroluminescence, analytical performance as well as the photochemistry mechanismsof the most efficient material—[Ru(bpy)32+]·(PF6)-2. The results show that the oxygensensor based on Light-Emitting Electrochemical Cell can be operated with low voltageat room temperature, offering strong electroluminescence that can be easily seen bynaked eyes. The sensor also offers rapid and reversible responses, a wide linear range.The results indicate that the sensor can be used to analyzing unknown sample. Inaddition, it has the potential to be an electro-optically dual monitored, and also to bevisual sensor device.Otherwise, the rest of the paper shows some initial research on thesuper-resolution analysis based on microspheres superlens. Due to the ‘Abbediffraction limit’, the imaging resolution of the conventional optical microscopeis about half the incident light wavelength, thus for ordinary white-lightmicroscope, the best resolution is~200nm. How to overcome the diffraction limit, earning higher resolution in nanoscale is always a hot and challengingissue. In this work, we confirmed the super-resolution capability of solidmicrospheres such as silica(SiO2) and polystyrene, imaged~100nm porousstructures, and earn a50nm resolution. We then applied the silica superlens intofluorescence imaging, and managed to image~100nm porous structure. Resultsshow that it might be a potential way of fluorescent imaging withsuper-resolution. What’s more, we designed and fabricated a series ofmicrofluidic chip and did some elementary studies on fabricating liquidmicrospheres by microfluidic technic.