Ultrasensitive and Label-Free Detection of the Measles Virus Using an N‑Heterocyclic Carbene-Based Electrochemical Biosensor

• Published in: ACS sensors 2020-09, Vol.5 (9), p.2747-2752
• Main Authors: Mayall, Robert M, Smith, Christene A, Hyla, Alexander S, Lee, Dianne S, Crudden, Cathleen M, Birss, Viola I
• Format: Article
• Language: English
• ISSN: 2379-3694; 2379-3694
• DOI: 10.1021/acssensors.0c01250

With the current intense need for rapid and accurate detection of viruses due to COVID-19, we report on a platform technology that is well suited for this purpose, using intact measles virus for a demonstration. Cases of infection due to the measles virus are rapidly increasing, yet current diagnostic tools used to monitor for the virus rely on slow (>1 h) technologies. Here, we demonstrate the first biosensor capable of detecting the measles virus in minutes with no preprocessing steps. The key sensing element is an electrode coated with a self-assembled monolayer containing the measles antibody, immobilized through an N-heterocyclic carbene (NHC). The intact virus is detected by changes in resistance, giving a linear response to 10–100 μg/mL of the intact measles virus without the need to label or process the sample. The limit of detection is 6 μg/mL, which is at the lower limit of concentrations that can cause infections in primates. The NHC-based biosensors are shown to be superior to thiol-based systems, producing an approximately 10× larger response and significantly greater stability toward repeated measurements and long-term storage. This NHC-based biosensor thus represents an important development for both the rapid detection of the measles virus and as a platform technology for the detection of other biological targets of interest.