Low-cost rapid diagnostic for COVID-19

A COVID-19 diagnostic approach, utilizing a SARS-CoV-2 binding biosensor, that allows for real-time virus detection, without the need for sample processing, ultimately leading to population-level surveillance, outbreak tracking, reduced healthcare costs, improved treatment outcomes, and saved lives.

Problem:
SARS-CoV-2, the virus that causes COVID-19, continues to kill people at a staggering pace, threatening both public safety and the global economy. According to the World Health Organization, as of November 2020, there were more than 50 million reported cases of COVID-19 worldwide, resulting in over 1.2 million deaths. Due to the rapid rate of transmission and risk of secondary bacterial infections, there is an urgent need to develop approaches to quickly detect and diagnose viral infection in order to inform subsequent treatment and to enable population-level surveillance and outbreak tracing. Currently, available diagnostics are limited by their high cost of production and slow detection time, thus hindering their widespread use in the population.

Solution:
The de la Fuente lab has created a low-cost, pocket-sized biosensor that is capable of diagnosing COVID-19. The sensor, which costs 7¢ to produce, is a printed circuit-board electrode that can diagnose SARS-CoV-2 infected samples in real time. The device can be implemented on a large-scale or connected to a smartphone to enable personalized, viral detection.

Technology Overview:
The biosensor’s electrode is functionalized by anchoring human Angiotensin Converting Enzyme 2 (ACE2), the host target of SARS-CoV-2, to the surface. A small saliva sample (2-10 μL) is transferred to the device. The selective binding between ACE2 and the spike protein of SARS-CoV-2 is measured through electrochemical impedance spectroscopy (EIS) and detected using a potentiostat. Variations in the resulting signal are used to obtain qualitative and quantitative results for the diagnosis of COVID-19. This versatile technology has the potential to be modified and applied in the diagnosis of other viral infections.

The novel diagnostic device can detect the SARS-CoV-2 virus within 4 minutes, a vast improvement on the current state-of-the-art which has a detection time of 30 minutes. Ongoing studies have demonstrated its powerful diagnostic capabilities, achieving 97% accuracy (96% sensitivity, 100% specificity) in detecting SARS-CoV-2, when compared to RT-qPCR results. Additional efforts are being made to incorporate the sensor into protective face masks for continuous infection monitoring.

Figure: (A) Functionalization of electrodes with ACE2 (B) Virus present in samples can be detected by the interaction of its spike protein with ACE2 (C) Samples are added to the surface of the electrode and impedimetric measurements determine whether the samples are infected.

Advantages: