Biasing and ultra-sensitive interfacing circuit for an OFET-based troponin biosensor
摘要
This paper presents a comprehensive analysis of a novel Equivalent Circuit Model tailored for current-based biosensors, explicitly focusing on current-based troponin biosensors, with an output range from 3 µA to 6 µA, showing sensitivity and limit of detection of 0.0352 µA/(µm)−1 and 0.7294 µA, respectively. The study introduces an innovative micro-ampere to a milli-voltage current-to-voltage interfacing circuit that seamlessly integrates troponin OFET-based sensors. The proposed circuit is evaluated through rigorous simulations in terms of key performance metrics, including power consumption, voltage-to-current sensitivity, dynamic range, linearity of transfer characteristics, noise immunity, and area for IC fabrication. Comparative analyses with a basic Op-Amp-based current-to-voltage converter reveal significant enhancements in linearity and noise immunity for the proposed circuit, albeit at the expense of increased power consumption. Quantitative results show a 5% improvement in linearity and a 17.6% enhancement in noise immunity for the proposed circuit under 2.5 V biasing conditions, compared to the 1.35 V biasing scenario. The study emphasizes the critical importance of balancing performance metrics in interfacing circuit design to achieve optimal functionality and efficiency in troponin sensor applications.