Boron-doped carbon quantum dots: a 'turn-off' fluorescent probe for dopamine detection.

Boron-doped carbon quantum dots (size 2.3 nm) were fabricated by a modified hydrothermal carbonization one-pot synthesis protocol using 4-hydroxy phenylboronic acid as the common precursor that provided seed for the formation of carbon quantum dots as well as the dopant. These quantum dots exhibited excellent properties, namely good aqueous dispersion, strong fluorescence emission, good environmental stability, high selectivity and sensitivity towards the neurochemical dopamine even in the absence of any linker, functionalizing agents or enzyme. It is shown that this material can be used as a 'turn-off' fluorescent probe for the detection of even low concentrations of dopamine with a limit of detection (3σ/S) of about 6 μM. The simplicity of the synthesis protocol and the ease of dopamine detection define the novelty of this approach.