關鍵字： batch-injection-analysis (BIA)； calorimetric biosensor； medical thermistor； hydrogen peroxide； biocalorimetry
摘要： This paper presents a calorimetric biosensor and detection system based on a medical thermistor and a disposable polymeric reaction cell for detecting hydrogen peroxide in a batch-injection-analysis (BIA) process. Single thermistor was used as a calorimetric sensing element to measure temperature change in an enzyme-substrate exothermic reaction. The detection system consists of a transducer, an analog-to-digital conversion device with 16-bits resolution, a single chip microcontroller, and a universal-serial-bus (USB) interface to communication with personal computer. A computer program for dynamic data acquisition and recording was developed to monitor and record temperature profile of the calorimetric biosensor during reaction. Disposable PMMA polymeric cell was used as a reaction cell to fill enzyme and the reaction medium. As results, after linearization of calorimetric biosensor and primary grade calibration, the accuracy of temperature measurement for the developed system is 0.001 C and correlation coefficient R2 is 0.999 at temperature between 20 and 30 C. When the calorimetric biosensor was incorporated with the detection system, it showed a linear range between 3.125 x 10-2 M to 1 M for hydrogen peroxide concentration detection with a correlation coefficient R2 of 0.9991. Compare with other types of hydrogen peroxide sensor and detection systems, the developed BIA enzyme calorimetric biosensor and detection system has a potential of low cost and high precision for hydrogen peroxide determination for the concentration at toxic and hazardous level. The system could be applied further for other biocalorimetry researches.