Thermal Management and Surface Passivation of a Miniaturized PCR Device for Traditional Chinese Medicine

Abstract

A robust, efficient, low power and ready-to-integrate Si-based miniaturized reactor for polymerase chain reaction (PCR) has been developed. With this chip reactor, we have demonstrated DNA amplification of Traditional Chinese Medicine (TCM) named Fritillaria cirrhosa (similar to 600 bp) as efficient as that of the conventional thermal cycler. This 8 mul reactor has Pt heaters and temperature sensors integrated on top of a thin Si membrane capping the reaction chamber for accurate temperature control and rapid thermal cycling of the PCR reagent. A temperature accuracy of +/-0.05 degreesC together with 5 degreesC/s heating rate and 3.5 degreesC/s cooling rate has been achieved using digital proportional and integral (PI) control algorithm. Moreover, a power of 1.5 W is sufficient to heat up the reaction chamber to DNA melting temperature of 95 degreesC. The low thermal budget PCR module can eventually be integrated with sample preparation, product separation and detection modules to realize a portable and battery-operated "Genechip" for bioassay as well as drug development of TCM.