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Design And Fabrication Of The Light Addressable Potentiometric Sensor System

Posted on:2002-03-25Degree:MasterType:Thesis
Country:ChinaCandidate:W G LiangFull Text:PDF
GTID:2168360032951961Subject:Physical Electronics
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Design and Fabrication of the Light AddressablePotentiometric Sensor SystemLiang Weiguo (Physical Electronics)Directed by Pro. Han JinghongThe light addressable potentiometric sensor (LAPS) is a kind of sensors based on the electrolyte-insulator-semiconductor (EIS) structure. Electronics technology, optical technology and mechanical technology are applied to the LAPS system. It is mainly used to image the distribution of special ions and do multi-parameter detection. Since the introduction of the LAPS, it has been used to many fields.This paper describes the mechanism of the light addressable potentiometric sensors (LAPS) in detail from the viewpoint of Semiconductor Physics, and introduces the fabrication of a biochemical LAPS system used for multi-parameter detection. The LAPS chip of this system is 1 60j.tm thick. An array of sensitive membranes are distributed on the surface of the chip. Each of these sensitive membranes responses to only one parameter. An 5 X 7 JR-LED matrix is used as the light source, which is directed to the backside of the chip. Different parameters can be detected by illuminating different sites with the LED matrix. Besides the chip and the LED matrix, the whole system consists of a lock-in amplifier, a micro-controller system, an addressing circuit, a potentiostat, a flow injection system and a personal computer. Users can control the whole system through the Windows application in the PC. Most functions can be done automatically.Some research work have been done to find how the thickness of the chip, the the linearity of the I-V curve and frequency affect the performance of the LAPS system. Trough experiments, the best parameters suitable for this system are found. Some experiments have been arranged to detect urea and penicillin with this system. These experiments are used to evaluate the multi-parameter detection ability of the system. The results show that we have realized a general platform used to detect electrochemical and biological parameters. This LAPS system is easy to operate, and possesses the fundamental ability to undertake multi-parameter detection work. The system is very promising, and the research work has provided the base for putting the system into practical use.
Keywords/Search Tags:LAPS, EJS, sensitive membrane.
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