doi:10.1038/nindia.2014.64 Published online 13 May 2014
Researchers have developed a sensitive biosensor that can detect and
measure extremely low concentrations of C-reactive protein, a biomarker that
indicates the onset of cardiac diseases1. They made the sensor using a
special type of carbon nanofibre.
The detection and quantification of biomarker proteins are critical for diagnosing and treating cardiovascular diseases. One such biomarker is C-reactive protein, which is produced in the liver and triggers inflammation in the body when it enters the bloodstream. The blood concentrations of this protein rapidly increase before the onset of cardiac diseases, and thus measuring the levels of this protein can be helpful for predicting the risks of cardiac diseases.
The researchers fabricated the biosensor by growing vertically aligned carbon nanofibres on silicon wafers. They then attached the probe molecule anti-C-reactive protein to the biosensor surface. This probe protein was used to capture C-reactive protein. They carried out electrochemical studies to determine the efficacy of the biosensor in measuring C-reactive protein levels in solutions.
The researchers exposed the biosensor to solutions containing different concentrations of C-reactive protein. They found that current decreased when C-reactive protein bound to the surface of the biosensor, indicating the specific concentration of this biomarker protein. The current decreased at faster rates for lower biomarker protein concentrations and lower rates for higher protein concentrations.
The biosensor could detect extremely low concentrations of C-reactive protein, having a detection limit of 11 nanogram/millilitre. In addition, this biosensor can provide portable and multiple protein detection platforms, allowing rapid diagnosis and treatment of cardiac diseases.
1. Gupta, R. K. et al. Label-free detection of C-reactive protein using a carbon nanofiber based biosensor. Biosens. Bioelectron. 59, 112–119 (2014)