Nucleic-acid amplification and analyses techniques have become the most significant tools for many important applications. Besides the frequent molecular diagnosis of diseases and assessments of therapies in clinics and hospitals, they are also broadly applied in environment surveillances, food processing industry and agricultural researches. The amplification of the amount of nucleic-acid analyte in the test sample is essential for sufficient detection. Polymerase chain reaction (PCR) is the major process to amplify interesting nucleic-acid. However, it always spends too much analyte volume and 3~4 hours for carrying out the reaction. In the study, we construct a novel micro-droplet PCR device and PCR chips utilizing MEMS techniques.

The temperature variation of the micro-droplet PCR device achieves 1 ℃ per second. Moreover, we develop the micro-droplet PCR chips fabricated by silicon wafer with two concentric circles structure. Then, the chip is coated with a layer of PPFC (plasma polymerization fluorocarbon) film on its surface. Utilizing the MEMS process, the solution of nucleic-acid reactants is concentrated in the inner circle and 5μL the mineral oil in the outer circle is covered on the reaction solution. Comparing to the traditional PCR method, the micro-droplet PCR device and chips have the advantages of extremely low-volume reaction solution (only 1~2μL) and rapid amplification time (~30 minutes). The novel micro-droplet PCR device is quite promising to efficiently DNA amplify.