Fluorescent biosensor for the selective determination of dopamine by TGA-capped CdTe quantum dots in human plasma samples

As a vital catecholamine neurotransmitter released by the brain in human central nervous system, dopamine (DA) plays an important role in a wide range of physiological functions and the mechanism of actions in human body, and its accurate detection is required in medicine. The present study reports a novel, simple and cost-effective nano-biosensor based on a thioglycolic acid (TGA)-capped cadmium telluride (CdTe) quantum dots (QDs) for the sensitive detection of DA in alkaline media. The assembled QDs-based biosensor showed a linear working range of 0.5-10 μM and a detection limit of 0.35 μM. The highest recovery of 97% was obtained by using the prepared biosensor for the detection of DA in human blood plasma samples. Additionally, the biosensor exhibited high selectivity toward DA without the interfering effects of biomolecules including some amino acids and chlorides. The concept of TGA-capped CdTe QDs will open up a new insight into the determination of DA in biological fluids where DA is at low levels.