An eco-friendly, simple, and sensitive fluorescence biosensor for the detection of choline and acetylcholine based on C-dots and the Fenton reaction.

A simple and novel method is proposed for the preparation of Carbon dots (C-dots) with excellent properties. We firstly demonstrated that the fluorescence of C-dots decreased apparently in the presence of H2O2 and Fe(2+). Based on the this finding, C-dots are successfully adopted as probes for the detection of H2O2. After the experimental conditions are optimized, the limit of detection (LOD) for H2O2 is found to be 0.1 μM. Furthermore, we established an eco-friendly, simple and sensitive biosensor for the detection of choline and acetylcholine (ACh) based on the detection of H2O2 using C-dots as probes. The detection limit for choline is 0.1 μM and the linear range is 0.1-40 μM. The detection limit for ACh is found to be 0.5 μM and the linear range is 0.5-60 μM. The excellent performance of the proposed biosensor shows that this method possesses the potential for practical application.