Digital-Based Potentiostat and Mesoporous Microelectrode Co-Design for Non-Enzymatic Glucose Detection at 0.3V- VDD and 1.65nW-Power

This paper presents a proof-of-concept ultra-low voltage and ultra-low-power chronoamperometric sensing platform for non-enzymatic glucose detection, based on the co-design of a reconfigurable digital-based (DB) potentiostat and a mesoporous platinum (Pt) microelectrode. The DB potentiostat enables current readout and direct digitization from a 0.3V supply at nanowatt-level power, while the microelectrode geometry and mesoporous Pt nanostructuring provide non-enzymatic glucose sensitivity at physiologically relevant concentrations within an electrochemical operating window compatible with the voltage and power constraints of the readout. A frequency-domain signal and noise model of the DB potentiostat is derived for the first time and validated through simulations and measurements, providing a quantitative basis for the electrochemical/readout co-design. Fabricated in 130nm CMOS, the DB potentiostat achieves 5.6 pArms input-referred noise, corresponding to a 16.8 pA circuit level minimum detectable current, while consuming 1.65nW at VDD=0.3V. Electrochemical currents from 600 pA to 650 nA are experimentally measured with R2=0.991 linearity under ferrocyanide test conditions. Non-enzymatic glucose measurements with mesoporous Pt microelectrodes at physiologically relevant concentrations, under aerobic conditions and with ascorbic acid as an interferent, demonstrate, to the best of the authors’ knowledge, the lowest reported power consumption for CMOS non-enzymatic glucose readout, supporting the potential of the proposed platform for emerging point-of-care diagnostics applications.