Loop-mediated isothermal amplification-based electrochemical sensor for detecting SARS-CoV-2 in wastewater samples

• Published in: Journal of environmental chemical engineering Vol. 10; no. 3; p. 107488
• Main Authors: Ramírez-Chavarría, Roberto G., Castillo-Villanueva, Elizabeth, Alvarez-Serna, Bryan E., Carrillo-Reyes, Julián, Ramírez-Zamora, Rosa María, Buitrón, Germán, Alvarez-Icaza, Luis
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01-06-2022
• Subjects: Electrochemical sensor; Epidemiology; Redox intercalator; RT-LAMP; SARS-CoV-2; Wastewater; RT-LAMP; SARS-CoV-2; Electrochemical sensor; Wastewater; Epidemiology; Redox intercalator
• ISSN: 2213-3437; 2213-2929; 2213-3437
• DOI: 10.1016/j.jece.2022.107488

The current pandemic COVID-19 caused by the coronavirus SARS-CoV-2, has generated different economic, social and public health problems. Moreover, wastewater-based epidemiology could be a predictor of the virus rate of spread to alert on new outbreaks. To assist in epidemiological surveillance, this work introduces a simple, low-cost and affordable electrochemical sensor to specifically detect N and ORF1ab genes of the SARS-CoV-2 genome. The proposed sensor works based on screen-printed electrodes acting as a disposable test strip, where the reverse transcription loop-mediated isothermal amplification (RT-LAMP) reaction takes place. Electrochemical detection relies upon methylene blue as a redox intercalator probe, to provide a diffusion-controlled current encoding the presence and concentration of RT-LAMP products, namely amplicons or double-stranded DNA. We test the performance of the sensor by testing real wastewater samples using end-point and time course measurements. Results show the ability of the electrochemical test strip to specifically detect and quantify RT-LAMP amplicons below to ~ 2.5 × 10−6 ng/μL exhibiting high reproducibility. In this sense, our RT-LAMP electrochemical sensor is an attractive, efficient and powerful tool for rapid and reliable wastewater-based epidemiology studies.
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•Wastewater-based epidemiology and surveillance.•Fast and reliable of SARS-CoV-2 genome detection.•Loop-mediated isothermal amplification with redox intercalator probe.•Electrochemical sensing with low-cost screen-printed-electrodes.