玻璃结构PCR芯片快速精密温控及实验验证

Rapid and Precise Temperature Control and Experimental Verification of PCR Chip

摘要:

PCR芯片作为即时检测技术的一种核心生化分析器件,在疾病快速现场检测、便携式分析中有着广泛应用。温度快速精密控制对提高PCR芯片的扩增效率和准确性极为重要。相较于聚合物材料,玻璃材料具备优良的生物兼容性、导热性和密封性。设计并制作了一种全玻璃结构的PCR芯片,以PT100温度传感器和恒流源组成温度检测电路,将温度值线性转换成电压值。采用STM32控制器作为核心处理器,完成电压值的数字化采集。结合积分分离PID算法,对加热电极和风扇施加驱动电流和控制电压,实现对PCR芯片的快速精密温度控制。实验结果表明,该PCR芯片可获得6℃/s的升温速率以及3℃/s的降温速率,控温精度为0.4℃,优于当前市场上大多数PCR仪的性能。生物扩增实验验证了PCR芯片DNA扩增的有效性。

Abstract:

As a core device for biochemical analysis in point-of-care testing (POCT) technology, PCR chip is widely used in rapid on-site disease detection and portable analysis. Rapid and precise temperature control is extremely important to improve the amplification efficiency and accuracy of PCR chip. Compared to polymer materials, glass materials have excellent biocompatibility, thermal conductivity and sealing properties. A whole glass structure PCR chip was designed and fabricated. The temperature detection circuit is composed of PT100 temperature sensor and constant current source, which can linearly convert temperature into voltage. Using STM32 controler as the core processor to acquire the digital voltage, the system applies integral separation PID algorithm to apply driving current and control voltage to heating electrode and fan, thus fast and precise temperature control of PCR chip can be realized. Eexperimental verification shows that the PCR chip can obtain a heating and cooling rate of 6 and 3℃/s, respectively, and the temperature control accuracy is 0.4℃. Bio-amplification experiment verifies the effectiveness of PCR chip for DNA amplification.