CdS quantum dot-chitosan-anti SP17 nanohybrid as a potential cancer biomarker

Abstract Sperm protein 17 (SP17) is selectively overexpressed in several human malignancies including ovarian carcinoma, but is absent or expressed at low levels in most normal tissues. In this research, a nanohybrid of cadmium sulphide (CdS)-chitosan-anti SP17 was developed for the first time. Chitosan was covalently conjugated with CdS-anti SP17 by using the 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (sulfo-NHS). The nanostructures were characterized by Fourier transform infrared spectroscopy (FIIR) and transmission electron microscopy (TEM). FTIR results demonstrated successful conjugation of chitosan to cadmium sulphide (CdS) quantum dots. The TEM images indicated formation of ultra-small nanocrystals with average diameters in the range of 3 nm. Moreover, ELISA result showed relatively high binding ability of QDs to the Sp17 recombinant antigen, which could be potentially used for detection and imaging of cancer tumors.