Yasaman Sadat Borghei - Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
Mohammad Reza Ganjali - Biosensor Research Center, Endocrinology & Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
Morteza Hosseini - Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.

Background: cysteine (cys) are associated with oxidative damage and metabolic disorders, which may lead to carcinogenesis. women with higher levels of homocysteine and cysteine were at a greater risk for developing breast cancer when their folate levels were low. Herein, we report new method to detection of cys on the synthesis of size-selected copper nanoclusters (CuNCs) with cysteine. With increasing concentrations of cysteine the larger cluster formated, resulting in appreciable changes in opticalproperties. Material and methods: The copper sulfate precursor was reduced by cys. copper sulfate solution was added to freshly prepared Cys spike in to serum. Then NaOH solution was added . Results and discussion: The size of the nocrystals were determined by SEM images and DLS. The components of the as-prepared CuNCs were characterized by FTIR spectrum. Conclusion: The presence of various concentration of Cys in a solution induces a decrease in the intensity of CuNCs emission. therefore the selective determination of cysteine with a lower analyte limit of 5 μM, can be carried out in aqueous solutions without the need for any sophisticated instrumentation

copper nanocluster, cysteine