Organic electrochemical transistors appear as an alternative for relatively low-cost, easy-to-operate biosensors due to their intrinsic amplification. Herein, we present the fabrication, characterization, and validation of an immuno-detection system based on commercial sensors using gold electrodes where no additional surface treatment is performed on the gate electrode. The steady-state response of these sensors has been studied by analyzing different semiconductor organic channels in order to optimize the biomolecular detection process and its the application to monitoring human IgG levels due to SARS-CoV-2 infections. Detection levels of up to tens of $\mathsf{\mu }\mathrm{g}{\mathrm{mL}}^{-1}$ with sensitivities up to 13.75% [$\mathsf{\mu }\mathrm{g}/\mathrm{mL}$]⁻¹, concentration ranges of medical relevance in seroprevalence studies, have been achieved.

This paper explores the development of a low-cost alternating current (AC) smart current generator using ARM Cortex-M33 microcontrollers with integrated peripherals, Digital to Analog Converters (DAC) and Operational amplifiers (OPAMPS). The system generates an AC voltage signal through the DAC, which is then converted to an AC using integrated operational amplifiers and passive components. The proposed design provides a compact, low-power, cost-effective solution which is suitable for optimized embedded system sensor design. Results show a signal-to-noise ratio (SNR) of up to 70 dB and a total harmonic distortion (THD) as low as 0.2%, illustrating the potential for advanced sensing applications.