Increase ACE2 Concentrations Embedded in the Memristive Electrochemical Sensor Membranes Promote Direct Reagent-free Sensing S1 Antigen of SARS-Cov2 Virus

E.T. Chen, J.T. Thornton, S-H Duh
Advanced Biomimetic Sensors, Inc.,
United States

Keywords: S1 antigen memristive sensor, reversible membrane potential, ratio of action potential/resting potential


Fast and precise detection of the presence of a single SARS-Cov2 virus particle is a very challenging topic because of protein interference. We developed new types of memristive electrochemical sensors with embedded angiotensin-converting enzyme 2 (ACE2) cross-linked with organic polymers self-assembled on gold chips. Our goals are to change the ACE2 concentrations in the polymer mixtures from 4.5, 57.5 to 230 nM as for sensors 1, 2, and 3, respectively, to study the ACE2 factor impacting the spiking protein S1 of SARS-Cov2 virus communicating with the sensor, that may reflect the eternal equilibrium energy change, cell reversible membrane potential (RMP) change in short monitoring time under reagent-free and antibody-free conditions. Results shown S1 antigen mostly impacted sensor 1’s Open Circuit Potential (OPO) compared with controls, to most negative OPO data; as consequence, it has the highest oxidative i-V curves and more data in the ratio of action potential vs. resting potential located in the unsafe zone, compared with sensor 2 and sensor 3 using Double Step Chronopotentiometry (DSCPO) method. Sensor 3 was used for the quantitation of S1 using the OPO method monitoring 120 seconds per sample, over the concentration range between 5 aM to 100 pM (total sample n=18), produced an RSD 0.1% related to the mean OPO potential produced at the single virus particle concentration (p