CMOS Image Sensor-based Immunodetection by Refractive-Index Change

Abstract

A complementary metal oxide semiconductor (CMOS) image sensor is an intriguing technology for the development of a novel biosensor. Indeed, the CMOS image sensor mechanism concerning the detection of the antigen-antibody (Ag-Ab) interaction at the nanoscale has been ambiguous so far. To understand the mechanism, more extensive research has been necessary to achieve point-of-care diagnostic devices. This research has demonstrated a CMOS image sensor-based analysis of cardiovascular disease markers, such as C-reactive protein (CRP) and troponin I, Ag-Ab interactions on indium nanoparticle (InNP) substrates by simple photon count variation. The developed sensor is feasible to detect proteins even at a fg/mL concentration under ordinary room light. Possible mechanisms, such as dielectric constant and refractive-index changes, have been studied and proposed. A dramatic change in the refractive index after protein adsorption on an InNP substrate was observed to be a predominant factor involved in CMOS image sensor-based immunoassay.

Real-time DNA Amplification and Detection System Based on a CMOS Image Sensor

“…The nanometer thickness of the substrates could be analyzed by the CMOS sensor as photon detection techniques. 27,28 Based on this concept, we carried out the LAMP analysis using a CMOS sensor. For the LAMP assay, various concentrations of DNA samples were added into the polypropylene well integrated CMOS sensor, which was kept on the thermal block at 63 C, and provided an LED light source for the photon count.…”

Overview of CMOS image sensor use in molecular diagnostics

“…CMOS sensor involved in: protein array development for protein diagnosis [32], fluorescence detection for protein and peptide diagnosis [4], CMOS based detection of AgeAb interaction on nanoparticle substrate [6], chemiluminescence analysis for AgeAb diagnosis [33], microarray platform development for DNA, RNA hybridization [16], DNA array development for DNA analysis [34], integrated program for sequence analysis [35], PCR approach for DNA amplification [7], integrated platform for gas sensing [36] optical sensing imager for the bio-molecule detection [37], microscopic approach for biomarker detection [38], and color density analysis for blood glucose monitoring [39]. detection of various AgeAb interactions such as interferon gamma [49], C-reactive protein (CRP) [50], Troponin I [51], HIV [28], and hepatitis B (HBV) [52] and label free electrical detection of hTSH [53]. Also, number of CMOS based cell sensors accomplished the cell monitoring with POC approach [54].…”

“…Further, this method could be performed without any expensive analytical tools, within a reasonable time, without multiple steps, and with minimal amount of sample. In addition, this group carried out the CMOS image sensor based detection of AgeAb interactions for cardiovascular markers of C-reactive protein, Troponin I [51], and infectious diseases such as HIV [28] and hepatitis B [52] with high sensitivity and specificity. The optical sensing method showed results as a digital number for easy read-out.…”

“…The optical sensing method showed results as a digital number for easy read-out. Moreover, this group demonstrated the methodology for CMOS image sensor-based AgeAb interactions based on refractive index changes [51]. AgeAb layers influenced the direction of light and the refractive index has decreased when protein layers increased on the substrate.…”

Whole blood glucose analysis based on smartphone camera module

“…[8][9][10] Also, we have successfully accomplished CMOS image sensor-based antigen-antibody interactions. [11][12][13][14] In addition, CMOS image sensors employing various glucose monitoring methods, including continuous glucose monitoring method, 15,16 enzymatic glucose monitoring method, 17,18 and thermal-based glucose monitoring, 19 operate at the in vitro and in vivo levels. In addition, smartphones have proved efficient for calorimetric analysis.…”