Complementary metal-oxide semiconductor (CMOS) image sensor: an insight as a point-of-care label-free immunosensor.

The present paper examines the efficiency of a complementary metal-oxide semiconductor (CMOS) using an indium nanoparticle (InNP) substrate for the high-sensitivity detection of antigen/antibody interactions at concentrations as low as 100 pg/ml under normal light. Metal NPs coated with antigen/antibody layers act as a dielectric layer on the conducting sphere, which enhances the number of photons hitting the sensor surface through a light-scattering effect. This photon number is proportional to the digital number observed with the CMOS sensor for detecting antigen/antibody interactions.