An artist’s rendering shows how the sensor contains areas that each detect a different indicator of COVID-19 infection. Image credit: Caltech
A feature of the COVID-19 The virus that makes containment so difficult is that it can easily be passed on from one person who is not yet showing signs of infection to another. The carrier of the virus may be very comfortable and go about their daily chores – taking the virus to work, to a family member’s home, or to public gatherings.
A crucial part of the global effort to contain the spread of the pandemic is therefore developing tests that can quickly identify infections in people who are not yet symptomatic.
Now, Caltech researchers have developed a new type of multiplex test (a test that combines multiple types of data) with an inexpensive sensor that can diagnose COVID infection at home by quickly analyzing small amounts of saliva or blood, without the involvement of a doctor, in less than 10 minutes.
The research was carried out in the laboratory of Wei Gao, Assistant Professor in the Medical Technology Department of Andrew and Peggy Cherng. Previously, Gao and his team developed wireless sensors that can monitor conditions like gout and stress by detecting extremely low levels of specific compounds in blood, saliva, or sweat.
The sensor element is made of thin plastic that has been etched with a laser. Image credit: Caltech
Gaos sensors are made of Grapha sheet-like form of carbon. A plastic sheet etched with a laser creates a 3D graphene structure with tiny pores. These pores create a large surface area on the sensor, making it sensitive enough to detect it with a high value accuracyCompounds that are only present in very small quantities. In this sensor, the graphene structures are coupled with antibodies, molecules of the immune system that are sensitive to certain proteins, for example on the surface of a COVID virus.
Earlier versions of the sensor were impregnated with antibodies to the stress-associated hormone cortisol and urea acidwhich causes gout at high concentrations. The new version of the sensor that Gao named SARS-CoV-2 RapidPlex contains antibodies and proteins that can be used to detect the presence of the virus itself. antibodies made by the body to fight the virus; and chemical markers of inflammation that show the severity of COVID-19 infection.
“This is the only telemedicine platform I’ve seen that can provide information about the infection in three types of data from a single sensor,” says Gao. “In just a few minutes, we can check these values all at once, giving us a complete picture of the infection, including early infection, immunity and severity.”
When connected to supporting electronics, the sensor can wirelessly transmit data to the user’s mobile phone via Bluetooth. Image credit: Caltech
Established COVID testing technologies typically take hours or even days to produce results. These technologies also require expensive, complicated equipment, while Gao’s system is simple and compact.
To date, the device has only been laboratory tested on a small number of blood and saliva samples taken for medical research purposes from people who tested positive or negative for COVID-19. Although preliminary results suggest the sensor is very accurate, a larger test will need to be done on real patients instead of laboratory samples, Gao warns, to definitively determine its accuracy.
Now that the pilot study is complete, Gao plans to next test how long the sensors will last with regular use and test them with COVID-19 patients in the hospital. After testing in the hospital, he wants to evaluate the suitability of the tests for home use. After testing, the device must receive regulatory approval before it is available for general home use.
“Our ultimate goal is really home use,” he says. “In the following year, we plan to send them out to people at high risk for home testing. And in the future, this platform could be modified for other types of infectious disease testing at home. ”
The paper, entitled “SARS-CoV-2 RapidPlex: A Graph-Based Multiplex Telemedicine Platform for Fast and Inexpensive Diagnosis and Monitoring of COVID-19” was published online and appears in the December issue of the Diary matter. Co-authors are the former postdoc for medical technology Rebeca M. Torrente-Rodríguez, the medical students Heather Lukas, Jiaobing Tu (MS ’20), Jihong Min (MS ’19), Yiran Yang (MS ’18) and Changhao Xu (MS ’20) ; and Harry B. Rossiter of Harbor-UCLA Medical Center.
Reference: “SARS-CoV-2 RapidPlex: A graph-based multiplex telemedicine platform for the quick and inexpensive diagnosis and monitoring of COVID-19” by Rebeca M. Torrente-Rodríguez, Heather Lukas, Jiaobing Tu, Jihong Min, Yiran Yang, Changhao Xu, Harry B. Rossiter and Wei Gao, October 1, 2020, matter.
DOI: 10.1016 / j.matt.2020.09.027
CaltechAUTHORS: 20201002-102234974
Research funding was provided by the National Institutes of Health; the Tobacco-Related Disease Research Program, a California state agency focused on reducing tobacco use; the Merkin Institute for Translational Research; and the Translational Research Institute for Space Health.
