Detection of C-Reactive Protein using network-deployable DNA aptamer based optical nanosensor

Aptamer based sensors have been observed to have excellent recognition capacity towards various types of target molecules such as metal ions, proteins and other biomolecules. In this study, we report an optical `turn off' nanosensor, which consists of a deoxyribonucleic acid aptamer attached to a quantum dot on the 5' terminus and gold nanoparticle on the 3' terminus. The sensor uses the principle of fluorescence resonance energy transfer to detect C - reactive protein. With an increase in the target concentration in the sensor, the photoluminescence intensity decreases resulting in an increase in quenching efficiency. The nanosensor has a limit of detection as low as 1.77 picomolar and is observed to be highly specific to C-reactive protein. It also successfully detects the target protein in clinical samples exhibiting around 10% quenching at 10 picomolar target concentration. Future work on this sensor will involve investigation of this sensor in an in vivo environment so that it can be deployed for inflammatory disease management.