Research Highlight

Optical sensor for heart disease

doi:10.1038/nindia.2014.149 Published online 6 November 2014

Researchers in Bangalore claim to have developed an accurate and highly sensitive optical sensor for the detection of C-reactive protein (CRP), a biomarker for cardiovascular diseases1.

C-reactive protein (CRP) is an acute phase protein, found in blood plasma and its concentration increases with the risk for cardiovascular diseases. CRP concentration below 1 mg/l represents low risk; between 1 and 3mg/l represents average risk and above 3mg/l represents high risk of cardiovascular diseases. CRP level decreases rapidly after recovery or treatment.

Commonly used CRP detection techniques include radio-immuno-assay, immuno-fluorescence, immuno-chemi-luminescence and standard enzyme immunoassay (ELISA). The detection limits in these techniques range between 0.1 and 0.2mg/L.

The technique reported by Ajay Sood and co-workers uses optical fiber Bragg gratings (FBGs). "FBGs are efficient optical devices in the field of biosensors with the Bragg wavelength and the transmission intensity as probing parameters," Sood told Nature India.

The researchers detected CRP by monitoring an etched FBG coated with an anti-CRP antibody-graphene oxide (GO) complex. The sensors show high specificity to CRP even in the presence of other interfering factors such as urea, creatinine and glucose.


1. Sridevi, al. Sensitive detection of C-reactive protein using optical fiber Bragg gratings. Biosens. Bioelectron. (2014) doi: 10.1016/j.bios.2014.10.033