Design Of Portable Ganophosphorus Pesticideresidue Detector Based On Enzyme Electrod

To develop a kind of portable examination instrument of ganophosphorus pesticide residue, this paper has designed the examination amplifying and monolithic integrated circuit processing system based on organophosphate hydrolase enzyme electrode biosensor. Main work includes designing examination process of the portable instrument, designing of the system circuit, designing and debugging of the system software and so on.First, this paper has designed the examination system's examination process, including making the organophosphate hydrolase enzyme electrode biosensor( making foundation electrode, fixing the organophosphate hydrolase enzyme), and making sure of its uniformity, then designing the working process of the portable instrument. It was designed to show the density directly, precisely to 10 ug/L. It also designed the work plan for following examination circuit.Second, this paper has designed the examination system's hardware circuit, including micro current examination circuit, monolithic integrated circuit control system and power source module. OP07, INA129 and LM358 were chosen for the micro current examination circuit. STC89C52 was chosen to control ADC0804 transation circuit and LCD1602 display circuit. LM78(9)XX series were chosen to supply work power for the whole system. It also chose appropriate simulation components to build a complete circuit.Third, discoverd the relationships between the time that weak current signal steady section lasts (x), and the tested fluid concentration (y): y=0.0084e0.0239x. Based on this, designed the data processing program. And it has used the serial port and the STC-ISP software, the HEX document was downloaded to the monolithic integrated circuit for debugging of the whole system..Such kind of ganophosphorus pesticide residue detecting system can examine the pesticide density within four minutes. It can identify densitiy that is higher than 0.00840g/L.