Abstract Rapid, inexpensive, and easy-to-use coronavirus disease 2019 (COVID-19) home tests are key tools in addition to vaccines in the world wide fight to eliminate national and local shutdowns. However, currently available tests for SARS-CoV-2, the virus that causes COVID-19, are too expensive, painful, and irritating, or not sufficiently sensitive for routine, accurate home testing. Herein, we employ custom-formulated graphene inks and aerosol jet printing to create a rapid electrochemical immunosensor for direct detection of SARS-CoV-2 spike receptor-binding domain (RBD) in saliva samples acquired noninvasively. This sensor demonstrated limits of detection that are considerably lower than most commercial SARS-CoV-2 antigen tests (22.91 ± 4.72 pg ml −1 for spike RBD and 110.38 ± 9.00 pg ml −1 for spike S1) as well as fast response time (∼30 min), which was facilitated by the functionalization of printed graphene electrodes in a single-step with SARS-CoV-2 polyclonal antibody through the carbodiimide reaction without the need for nanoparticle functionalization or secondary antibody or metallic nanoparticle labels. This immunosensor presents a wide linear sensing range from 1 to 1000 ng ml −1 and does not react with other coexisting influenza viruses such as H1N1 hemagglutinin. By combining high-yield graphene ink synthesis, automated printing, high antigen selectivity, and rapid testing capability, this work offers a promising alternative to current SARS-CoV-2 antigen tests.
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This content will become publicly available on December 27, 2024
Wearable MXene‐Graphene Sensing of Influenza and SARS‐CoV‐2 Virus in Air and Breath: From Lab to Clinic
The rapidly expanding severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and its variants demand a continuous monitoring method through portable and wearable devices. Utilizing the rich surface chemistry and high chemical‐to‐electrical signal conversion of 2D MXene‐graphene heterostructure thin films, a field‐effect‐transistor (FET) sensor, which has a flexible substrate to be assembled onto the mask and combines with a Bluetooth system for wireless transmission is developed, to detect the influenza and SARS‐CoV‐2 viruses in air and breath. At first, the developed sensors are examined in the laboratory through direct contact with sensing targets in solution form. The results show a low limit of detection (LOD) of 1 fg mL−1for recombinant SARS‐CoV‐2 spike protein and 125 copies mL−1for inactivated influenza A (H1N1) virus with high specificity in differing recombinant SARS‐CoV‐2 spike protein and inactivated H1N1 virus. Then the sensors are tested under various simulated human breathing modes through controlled exposure to atomizer‐generated aerosols in an enclosed chamber and mask coverage. The results show the high sensitivity of the developed sensors under varying distances to the source, viral load, flow rate, and enclosed conditions. At last, clinical tests are carried out to demonstrate the robustness and potential field applications of the sensors.
more » « less- NSF-PAR ID:
- 10482499
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials Technologies
- Volume:
- 9
- Issue:
- 3
- ISSN:
- 2365-709X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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