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

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 (~600 bp) as efficient as that of the conventional thermal cycler. This 8 Ill 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°C together with 5°C/s heating rate and 3.5°C/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°C. 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.