High Precision Dual-channel Electrochemical POCT Device with Automatic Adjustment of Current Detection Sensitivity

Electrochemical point-of-care testing (POCT) technology is widely used in clinical testing, health management, epidemic control, food safety monitoring, and drug detection. Existing electrochemical POCT devices are mostly single-channel tests with a simple detection index, fixed sensitivity, and limited test range. In this article, a dual-channel, high-precision electrochemical device with automatic analytic software is developed. Two independent channels with consistent performance can be operated at the same time, multiplying the detection efficiency. The digital potentiometer is adopted as the feedback resistor for the operational amplifier, and an automatic adjustment program is set up on the smartphone app to achieve automatic adjustment of current detection sensitivity. An automatic peak-seeking function is proposed, which can quickly locate and record the peak voltage and current. The current detection range from ±10 nA to ±2 mA with a sensitivity up to 10−8A and a current detection resolution as low as 0.062% (6.19 pA in the ±10 nA range) are obtained. The device has been carried out for the simultaneous detection of ascorbic acid (AA), uric acid (UA), and dopamine (DA) ( ${R}^{2} >0.977$ ). The results indicate that the dual-channel device is of wide linear detection range, high precision, and consistency. It provides a technical means and a test platform for accurate and timely diagnosis of relevant diseases and health monitoring.