Uniform and well dispersed metal sulfide semiconductor nanoparticles incorporated into matrices of alginate biopolymer are prepared by using a facile in situ method. The reaction was accomplished by impregnation of alginate with divalent metal ions followed by reaction with thioacetamide. XRD analysis showed that the nanoparticles incorporated in the polymer matrix were of cubic structure with the average particle diameter of 1.8 to 4.8 nm. Field emission scanning electron microscopy and high resolution transmission electron microscopy images indicated that the particles were well dispersed and distributed uniformly in the matrices of alginate polymer. FT-IR spectra confirmed the presence of alginate in the nanocomposite. The crystalline nature and thermal stability of the alginate polymer was found to be influenced by the nature of the divalent metal ions used for the synthesis. The proposed method is considered to be a simple and greener approach for large scale synthesis of uniform sized nanoparticles.

Alginate biopolymer stabilized CdTe quantum dot (QD) was prepared and it was encapsulated with folic acid conjugated chitosan for controlled drug delivery of anticancer drug 6-mercaptopurine (6-MP). In addition to alginate, chitosan enhances the stability of QD. Also, in addition to chitosan, alginate binds to the drug leading to enhance the loading efficiency of the resulting drug carrier. The drug release profile of the carrier was investigated by in-vitro. The present study has shown that this drug carrier is feasible for drug delivery and will be important beneficiary for cancer therapy.