Mazhar Sher

Florida Atlantic University, USA

Abstract

There is a dire need to develop portable, cost-effective, and user-friendly biosensing devices for resource-limited settings. The currently existing laboratory-based diagnostic methods require expensive reagents and highly trained personnel. Hence, these assays are not suitable for resource-constrained settings with very limited financial resources, basic healthcare infrastructure, and few trained healthcare professionals. In order to cater this problem, a portable, inexpensive, and easy to use disease diagnostic platform is developed for the treatment monitoring of HIV- 1 virus. The developed assay is used to quantify the CD4+ T cells using electrical impedance spectroscopy. It is a magnetic actuation platform that utilizes highly specific antibody-coated magnetic microparticles to isolate CD4+ T cells from a 30 μL drop of human blood sample. The isolated cells are lysed and subsequently quantified using electrical impedance spectroscopy. The developed assay showed a limit of detection of 25 cells / μL and provided reliable CD4+ T cell enumeration in the range of 25– 800 cells/μL. The developed rapid assay provided quantification results in 5 minutes time frame. There is no need of any off-chip sample preparation step. The human involvement has been minimized to a greater extent. This impedanceˇbased immunoassay has the potential to significantly improve the CD4+ T cells quantification process, especially for resource-limited settings.