CMOS image sensor based HIV diagnosis: a smart system for point-of-care approach

Abstract

We report on the use of a complementary metal oxide semiconductor (CMOS) image sensor in an immunodiagnostic system for detecting the human immunodeficiency virus (HIV). It is based on photon counting and the interaction of the HIV antigen (Ag) with respective antibodies, which are deposited in various thicknesses on indium nanoparticles (InNPs) substrate. The sensor measures the number of photons that depends on the concentration of HIV Ag and converts them into digital numbers. Photons are refracted on the protein adsorbed InNP substrate and hit the CMOS image sensor surface based on the Ag concentration. Topographical studies such as field emission scanning electron microscopy (FE-SEM) and fluorescence microscopy images are demonstrated the reliability of this scheme. Also, the UV-spectral studies proved the efficiency of the analysis with InNP substrate. The sensor is simple, compact, highly specific and accurate. Also, it can detect HIV at levels as low as 10 fg mL(-1). Therefore, the sophisticated system of the CMOS image sensor based immunodetection now requires point-of-care (POC) diagnosis.