Synthesis of surface modified quantum dots (QDs) having potential biological activities are great important in biomedicinal chemistry. Here, we have synthesized mercapto propanoic acid (MPA) and thiolactic acid (TLA) coated water soluble cadmium selenide (CdSe) QDs having biological activity. Dispersion of QDs into a biological fluid can form protein corona. Hence, the binding of CdSe QDs with the carrier protein, human serum albumin (HSA) have been executed using spectroscopic methods. The binding affinity order of CdSe QDs-HSA complexes were found in the order of 10 5 M À 1 at 298 K. CdSe QDs are also affects the binding affinities of dietary polyphenols (naringin: NG and naringenin: NRG) towards HSA. The synthesized CdSe QDs was employed to sensing of antibiotic lomefloxacin by fluorescence quenching mechanism. The detection limit was found 0.70-1.83 μg mL À 1 . The CdSe QDs also demonstrate the detection of lomefloxacin under uv light based on color change of the solutions.