Nanopore-based DNA sequencing technology features the advantages of label-free, low-cost, and rapid detection. However, the existing nanopore sequencing readout cell or array for the lower area and power consumption become prohibitive. This brief presents a low noise potentiostat readout array. Based on the five-transistor OPA, the half-shared amplifier reduces the area and power consumption of the cell by about 50%, and shows a good suppression effect on mid-to-high frequency noise in the output channel. As a result, high-throughput is achieved with low noise. The performance of the proposed array channel has been evaluated in 180-nm CMOS process, the input-referred current transient noise was 2.28pARMS, the power consumption was 2.2µW and the unit area was 10×12µm².