H.A. Alhadrami, G.A.R.Y. Suaifan, M.M. Zourob
King Abdulaziz University,
Saudi Arabia
Keywords: SARS-CoV-2; COVID-19; rapid biosensors; onsite detection; low-cost diagnostic assay
Summary:
Simple, timely and precise detection of SARS-CoV-2 in clinical samples and contaminated surfaces aid in lowering attendant morbidity/mortality related to this infectious virus. Currently applied diagnostic techniques depend on a timely laboratory report following PCR testing. However, the application of these tests is associated with inherent shortcomings due to the need for trained personnel, long-time, centralized laboratories and expensive instruments. Therefore, there is an interest in developing biosensing diagnostic frontiers that can help in eliminating these shortcomings at a relatively economical, easy-to-use, well-timed, run in the field precisely and sensitive technology. This study reports the development of fabricated Q-tips designed to qualita-tively and semi-quantitatively detect SARS-CoV-2 in clinical samples and contaminated non-absorbable surfaces. This colorimetric sensor is engineered to sandwich SARS-CoV-2 spike protein between the lactoferrin general capturing agent and the complementary ACE2-labeled receptor. ACE2 receptor is decorated with an orange-colored polymeric nanoparticle to generate an optical visual signal upon pairing with the SARS-CoV-2 spike protein. This colorimetric change of the Q-tips testing zoon from white to orange confirms a positive result. The visual detection limit of the COVID 19 engineered colorimetric Q-tip sensor was 100 pfu/mL within a relatively short turnaround time of 5 mins. The linear working range of quantitation was 103 - 108 pfu/mL. The engineered sensor selectively targeted SARS-CoV-2 spike protein and did not bind to another coronavirus such as MERS-CoV, Flu A and Flu B presented on contaminated surfaces. This novel detection tool is relatively cheap to produce and suitable for onsite detection of COVID 19 infection.