Topic of Research Seminar: Development of Liquid Crystals Based Biosensor for the Detection of HIV-1 Surface Glycoprotein-120
Abstract: HIV-1 (Human immunodeficiency virus-1) is the causative agent of deadliest disease AIDS (Acquired immunodeficiency disorder syndrome) with no cure and vaccine till now. Around 36.3 million died due to AIDS and AIDS related illnesses since the beginning of this disorder. However, early diagnosis may turn this fatal disease into manageable chronic disease leading to minimal death and economic loss. Since surface protein gp-120 of HIV-1 virus plays an important role in HIV-1 infection, we chose, gp-120 as a target protein for HIV-1 early detection. However, the detection of gp-120 during the early stage of infection is very difficult.
Conventional methods for HIV-1 detection are ELISA, Home HIV test, Rapid test, PCR, P24 antigen assay. These methods are either laborious, complicated or require additional tests for confirmation. Therefore, there is a dying need of a rapid and economical sensing system that can detect HIV-1 early and hence saves many lives by reducing the risk of virus transmission. Since liquid crystals (LCs) based bioassays have grown highly popular because of their label free nature, excellent sensitivity, and real time monitoring capacity, we aimed our study to design LCs based biosensing assays for HIV-1 detection. Furthermore, we have developed, and proposed LCs based biosensing assays by integrating LCs based biosensing with other techniques such as microfluidics and microcontact printing.
We report a label-free and simple approach for the detection of glycoprotein-120 using an aptamer-based LCs biosensing platform. The LCs are supported on the surface of a DMOAP modified glass slide with arrays of suitable concentration of B40t77 aptamer drops dispensed on the surface. This appropriate concentration of B40t77 aptamer drops allows the LCs to be homeotropically aligned. A pronounced topological change was observed on the surface due to a specific interaction between B40t77 and gp-120, which led to the disruption of the homeotropic alignment of LCs. This results in a dark-to-bright transition observed under a polarized optical microscope. With this developed biosensing assay platform, it was possible to not only identify gp-120, but obtained results were analyzed quantitatively through image analysis. The detection limit of the proposed biosensing platform was investigated to be 0.2 µg/mL of gp-120. Regarding selectivity of the developed platform, no response could be detected when gp-120 was replaced by other proteins, such as bovine serum albumin (BSA), hepatitis A virus capsid protein 1 (Hep A VP1) and immunoglobulin G protein (IgG). Due to attributes such as label-free, high specificity and no need for instrumental read-out, the presented biosensing platform provides the potential to develop a working device for the quick detection of HIV-1 gp-120.
Subject Field of Topic: Liquid Crystals based biosensing
Name of Speaker: Amna Didar Abbasi
University Email of Speaker: [email protected]
Affiliation of Speaker: NUST School of Chemical and Materials Engineering (NUST-SCME)
Date and Venue: December 13, 2022 at 1400 hrs, Seminar Halll, School of Chemical and Materials Engineering (SCME), NUST Islamabad Campus