Novel paper-based electrochemical system for detection of anti-spike protein antibodies from SARS-CoV-2

A novel disposable paper-based electrochemical biosensor for detecting anti-spike protein antibodies is presented, featuring the innovative use of carbon dots derived from a biological source and a liposome–biorecognition element complex. The optimized electrochemical sensing platform is described and characterized, regarding its structural and functional properties. The sensor showed a linear response between 0.0010 and 10 µg mL − 1 , demonstrating high sensitivity and a low limit of detection (LOD) of 1.78 pg mL − 1 , as well as good selectivity. Real nasopharyngeal swab samples were tested for the first time using this type of paper-based electrochemical system for anti-spike antibody detection. This approach was designed to mimic the virus's response while ensuring greater sensitivity and selectivity. Overall, a new electrochemical method for screening anti-spike antibodies was developed to monitor vulnerable populations for new SARS-CoV-2 infections and track the development of adaptive immunity within communities, contributing to the development of future point-of-care (POC) analysis without the need for specialized personnel or laboratory facilities.