Digital PCR is a newly developed absolute quantitative analysis technique after real-time quantitative PCR

which is widely used in early detection and diagnosis of diseases and microbial detection.However

in the detection of digital PCR microreactors

conventional optical detection methods require complex optical equipments while the application environment is restricted and the cost is high.Therefore

a kind of PCR droplet detection chip based on contactless conductivity detection was developed by replacing the traditional optical detection with conductivity detection

which could effectively reduce the cost of the digital PCR result readout system.By optimizing the electrode structure and arrangement

a 3D electrode structure composed of three parallel electrodes is adopted to reduce the relative error and improve the sensitivity

and the detection on ratio of negative to positive PCR reaction droplets is achieved.The detecting throughput of the chip reaches up to 100 pcs per second

with a good relativity(r2=0.998) in the DNA template concentration range of 0.5×104-3×104 copies/μL.