Carbon quantum dots as a co-reactant to Ru(bpy)32+ for electrochemiluminescence biosensing of cardiac troponin I

Carbon quantum dots are interesting materials for electrochemiluminescence as they can be used as luminophores and co-reactants. This research paper focuses on the use of carbon quantum dots as the co-reactant to Ru(bpy) 3 2+ in an electrochemiluminescence system. Most of the work reported in literature applied the Ru(bpy) 3 2+ /CQD ECL system for chemical sensors. In this work, we apply it to a biosensor for the detection of cardiac troponin I. The Carbon quantum dots were synthesized using a bottom-up method and were used to modify the surface of screen-printed electrodes for immobilization of the biomolecules. They were characterized by photoluminescence, ultraviolet-visible, Fourier transmission infrared spectroscopy and square wave voltammetry. When the carbon quantum dots were introduced to the system, an enhancement in the electrochemiluminescence intensity of Ru(bpy) 3 2+ was observed. An electrochemiluminescence immunosensor was developed for the detection of cardiac troponin I. Electrochemiluminescence immunosensor achieved a low limit of detection of 0.02 ng/mL. The sensor also had a detection time of 15 minutes, allowing for rapid detections.