摘要：Electrochemical impedance biosensors measure the impedance varies of the solution during the biochemical process, so it can realize label-free biological detection. However, the biological signal to be detected is very weak, thus requiring signal amplification circuit. Printed organic thin film transistor (OTFT) has many advantages such as low cost, flexible bending, biocompatibility, which is suitable for biological detection. This work built up amplification circuit for electrochemical impedance test based on OTFT, different concentrations of phosphate buffer solution (PBS) used as test samples were measured with the above circuit. The results show that OTFT-based circuit has a good implementation of signal amplification, which lay a foundation for the application of printed OTFT in the electrochemical impedance biosensors.