A design of fluorescence-based sensor for the detection of dopamine via FRET as well as live cell imaging

Abstract

Dopamine is an essential biomolecule and transmits neurological signals in humans and other animals. Either deficiency or excessive concentration of dopamine cause several diseases in human beings like Huntington’s disease, fatal genetic disorder, and Parkinson’s disease. This study demonstrates the fabrication of carbon dots (CDs) from porcine pancreatic lipase (PPL) via the pyrolysis method. These synthesized CDs are used as a fluorescence probe for the selective detection of dopamine with a limit of detection 20 nM. This selectivity is due to the tendency of dopamine to oxidize into dopamine-quinone, which adsorbed on the surface of CDs. The emission intensity of CDs can be effectively quenched by dopamine-quinone via fluorescence resonance energy transfer (FRET) process. The sensing mechanism was characterized by the fluorescence lifetime decay, zeta potential, and UV–visible spectroscopy analysis. More importantly, the synthesized CDs are also used for the naked-eye detection of dopamine and real samples analysis. Additionally, CDs showed low-cytotoxicity toward MDA-MB 468 cells, demonstrating their essential use for in vitro dopamine sensing.