In situ polymerization of aniline on carbon quantum dots: a new platform for ultrasensitive detection of glucose and hydrogen peroxide

A simple and ultrasensitive platform for the detection of glucose and hydrogen peroxide based on fluorescence resonance energy transfer between carbon quantum dots (CQDs) and polyaniline is described in this report. Briefly, during enzymatic oxidization of glucose, hydrogen peroxide is generated. The generated hydrogen peroxide, in turn, initiates oxidative polymerization of aniline on the surface of the CQDs in the presence of horseradish peroxidase. And the formation of a thin polyaniline layer efficiently quenches the fluorescence of the CQDs. It was observed that the quenching of the fluorescence is directly associated with the concentration of glucose and ultrasensitive detection of glucose down to submicromolar levels was achieved. In addition, since the formation of polyaniline on the CQD surface is directly associated with hydrogen peroxide, it was found that traces of hydrogen peroxide can be detected in a range of 0.5-50 mu M with good selectivity.