Attomolar detection of cytokines using a chemiluminescence immunoassay based on an antibody-arrayed CMOS image sensor

A chemiluminescence immunoassay based on a CMOS image sensor has been developed for simultaneous attomolar detection of cytokines. Attomolar level detection sensitivity is achieved through direct immobilization of antibodies on the surface of the CMOS image sensor and using a simple data accumulation process with noise calibration after the sandwich immunoassay. Here, the proposed method was showed that the logarithmic linear range for interleukin-5 (IL-5) detection is from 1 fg mL(-1) to 20 ng ml(-1) and the limit of detection (LOD) is 0.074 fg mL(-1), corresponding to a concentration of 7 aM. The LOD represents ca. 1 x 10(5)-fold improvement compared with use of conventional ELISA. Furthermore, the multiple targets including IL-2, IL-4, IL-5, and IL-6 can be detected with simultaneous and low-cost manner on array type CMOS image sensor, and we hope that this sensor system will be a powerful tool in biological studies. (C) 2015 Elsevier B.V. All rights reserved.