Spectrofluorometric assay using gold nanoparticles and cationic dye Rhodamine B for selective and sensitive detection of L-Cysteine in aqueous environment

L-Cysteine (abbreviated as L-Cys) is an important thiol containing amino acid which is found in human plasma and is known as the primary building block of protein. This amino acid is involved in many essential and important biological processes in our physiological system. Although the presence of L-Cys in our body has number of health benefits, but excess amounts of this amino acid in human plasma or urine causes several health problems such as neurotxicity1, urinary stones2 etc. So, it is of prime importance to detect L-Cys selectively and more accurately in order to prevent our body from various diseases. In this present study we address a mechanism for selective and sensitive sensing platform utilizing the interaction of colloidal gold nanoparticles and cationic dye Rhodamine B (RhB) towards the detection of L-Cys from the fluorometric change of the dye molecules in an aqueous environment.