Enrichment And Detection Integration Calorimeter Type Biosensor System Design And Experimental Research

The food sanitation, quality of people’s life and the environment problem is a challenging topic in our country and get more and more attention. The toxicity of heavy metal ion will cause irreparable harm to our body and the environment. The research on heavy metal ion pollution has a huge disparity compared to foreign.Several methods such as liquid and gas chromatography have been widely used to detect the Heavy metal ion content. These methods have a high sensitivity but their applications in real samples are limited because of their high demand for equipment and operator, long detecting time, interferences from electroactive species, ions and turbidity of samples.A novel thermal biosensor based on flow injection is developed here, which can quickly detect the heavy metal ion residue content based on the heat of enzyme catalysis reaction. The thesis is mainly about:1. Research on principles and methods for detection of enthalpy change. Flow injection method is used in our detecting system. Compared to the original thermal biosensor, the system flow path and detecting process of the new device is improved.2. The thermal biosensor is improved by fabricating mini-thermal sensor, designing the thermostat and so on. According to the technology of flow injection analysis and the trait of thermal biosensor, a new rapid detection thermal biosensor was designed and built.3. The performance of each part of the system was tested, and the results shows that the thermostat and heat preservation function work well; thermoelectric piles is composed of semiconductor refrigeration thermoelectric pair, and the sensitivity to temperature changing for4mV/K, and the variation has a good linear relationship; reaction chamber can get1.2mV signal peak, add in1g resin can be get0.9mV signal peak.4. Optimization of the system parameters is to improve the sensitivity to mini temperature. The best parameters:reaction temperature is37℃, system velocity is1mL/min, reaction chamber is filled lg resin. Different copper ions concentration for10-6,10-4,10-2mol/L, cause different inhibition rate of69%,73%and82%. The thermal biosensor can detect specific concentration range of heavy metal ion concentration, and lower concentrations of heavy metal ion can be detected by the Resin adsorption.