Teaching an old dog new tricks: A lipid membrane‐based electric immunosensor for real‐time probing of the spike S₁ protein subunit from SARS‐CoV‐2

Abstract

Fast, cheap, and easy to implement point‐of‐care testing for various pathogens constituted a game changer in past years due to its potential for early disease diagnosis. Herein, we report on the proof‐of‐concept of a simple method enabling in vitro detection of a structural spike protein subunit from the SARS‐CoV‐2 (S 1 ) in aqueous samples. At the core of this discovery lies the well‐known paradigm of monitoring the capacitive current across a reconstituted zwitterionic lipid membrane subjected to a periodic transmembrane potential, followed by the real‐time spectral analysis enabling the extraction of the second harmonic of the capacitive current. Subsequent changes in the amplitude of this harmonic recorded during lipid membrane–S 1 interactions were correlated with alterations induced in the inner membrane potential profile by the S 1 protein subunit adsorption, and were shown to be augmented by ionic strength, the presence of a specific monoclonal antibody designed against the S 1 subunit and the angiotensin‐converting enzyme 2 (ACE2) protein receptor, and uninhibited by the presence of other human serum proteins.

Highlights on the current state of proteomic detection and characterization with nanopore sensors

“…The final paper in the biosensing subset is offered by Asandei et al [8] who take an unconventional approach to biosensor development.…”

“…The final paper in the biosensing subset is offered by Asandei et al. [8] who take an unconventional approach to biosensor development. They describe a biosensor based on the interaction of a charged analyte with a membrane support using the second harmonic signal of the capacitive current under an externally applied oscillating electric field.…”