Characteristic investigation of a static micro polymerase chain reaction chip based on in situ electrochemical detection

Abstract

Aiming to meet the ever-increasing challenge of a low cost, portable and real-time sensitive detection polymerase chain reaction (PCR) system, a novel in situ electrochemical detection static micro PCR (EC-SµPCR) chip is designed and fabricated. The 10×10 mm EC-SµPCR chip comprises 12 micro reaction chambers, and each 1500×1000×60 µm chamber consists of three modules: a micro heater, a micro temperature sensor and a micro three-electrode system (MTES). Heating, cooling and electrochemical cyclic voltammetry (CV) experiments were carried out to investigate the performance characteristics of each module of the chamber in the EC-SµPCR chip. The results showed that the heating rate of the chip was 1.05°Cs−1 with only one micro heater, whereas the cooling rate was 1.01°Cs−1 with natural air cooling. It is worth noting that the bare MTES of the chamber directly detected the oxidation of single-stranded DNA (ssDNA, 10−6 M) with the CV method, furthermore, the oxidation peak current of ssDNA can be increased about 40% after a prepolarisation step. All three modules of the chamber in the EC-SµPCR chip work efficiently and reliably, which reveals that the entire chip is ready for further analysis trials.