Lab-on-PCB-Based Electrical Immunosensing Platform for Point-of-Care Detection of SARS-CoV-2

• Published in: IEEE sensors letters Vol. 7; no. 1; pp. 1 - 4
• Main Authors: Joshi, Anju, Vishnu G. K., Anil, P. K, Smitha, Kadandale, Ashlesh, R. S., Hari, Roy, Bidipta, Das, Manjula, Pandya, Hardik J.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.01.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antibodies; Antigens; Chemical and biological sensors; Circuit boards; Coronaviruses; Electrical impedance; electrical impedance sensing; immunosensing; Immunosensors; lab-on-printed circuit board (PCB); nucleocapsid (NC); Printed circuits; Proteins; rapid antigen test (RAT); SARS-CoV-2; Sensors; Severe acute respiratory syndrome coronavirus 2; spike; Surface impedance; Surface treatment
• ISSN: 2475-1472; 2475-1472
• DOI: 10.1109/LSENS.2022.3228306

The present work shows a multiplexed lab-on-printed circuit board (PCB) platform for label-free immunosensing of SARS-CoV-2 nucleocapsid and spike antigens based on electrical impedance measurements. The sensor consists of an interdigitated electrode of soft gold integrated on a PCB with microwells for sample loading. A mercaptoundecanoic acid-protein-G-based site-specific biofunctionalization strategy is employed to efficiently immobilize dual antibodies on the device surface toward the sensitive and rapid antigen test of SARS-CoV-2. Electrical impedance measurements carried out in a point-of-care setting using the PalmSens Sensit Smart system that could detect nucleocapsid and spike proteins with a detection limit of 40 and 20 pg each. Experiments with nasopharyngeal swab samples from N = 5 healthy and N = 14 SARS-CoV-2 positive subjects showed significantly different electrical responses for subjects with high viral load ( Ct < 25) compared with healthy subjects and control.