▎ 摘　　要

In the paper, the development and performance of an optical sensor for detection of neurotransmitters (dopamine) is presented. The concentration of dopamine is measured basing on fluorescence quenching of graphene quantum dots. In the sensor, the dopamine molecules coat the graphene quantum dots surface - in result, the quenching of fluorescence occurs due to the Forster resonance energy transfer. The changes in fluorescence correspond to specific concentrations of the neurotransmitter in tested samples, so it is possible to accurately determine the concentration of dopamine in the sample.