Electrochemical-sensor-assisted lab-in-a-cartridge (EC-LIC) for on-site detection of SARS-CoV-2 with a self-contained heating system

Abstract

Rapid and accurate detection of respiratory viruses is essential for controlling disease transmission and enabling effective public health responses, particularly in resource-limited settings. In this study, we present an electrochemical-sensor-assisted lab-in-a-cartridge (EC-LIC) platform for on-site detection of SARS-CoV-2 featuring a self-contained chemical heating system. The device incorporates rotational and gravity-driven fluid handling along with exothermic heating using calcium oxide and a flameless ration heater to generate controlled temperature gradients. Coupled with a CRISPR-Cas13a-based electrochemical sensor, the system enables direct detection of the SARS-CoV-2 N gene without nucleic acid amplification, achieving high sensitivity and specificity. Integrated with a handheld electrochemical reader, the EC-LIC operates as a fully automated sample-to-answer system, completing the assay within 40 min over a wide dynamic range from 1.0 & times; 10 degrees to 1.0 & times; 105 fg/mL with a limit of detection as low as 1.21 & times; 10- 1 fg/mL. Clinical validation using samples from 102 individuals (60 positive and 42 negative) demonstrated a sensitivity of 98% and a specificity of 90%. These results establish the EC-LIC as a robust nucleic acid detection platform for rapid clinical screening and early epidemic response.