Borovaya M. "Green" synthesis of fluorescent CdS quantum dots and characterization of their properties

New methods of biological synthesis of CdS quantum dots have been developed using such biological matrices as a bacterium Escherichia coli, basidial fungus Pleurotus ostreatus, "hairy root" culture of Linaria maroccana, cell suspension culture of Nicotiana tabacum (BY-2).It was shown that an absorption maximum of synthesized CdS quantum dots (E. coli) is in the range of 420 - 440 nm, luminescent maximum - at the wavelength of 443 nm. Absorption peak of 453 nm and luminescent maximumof 462 nm are typical for CdS quantum dots, which are synthesized using P. ostreatus. For quantum dots obtained with L. maroccanait was observed an absorption maximum of 398 nm and luminescentpeak at 462 nm, whereas for quantum dots produced using N. tabacum (BY-2) absorption and luminescent maxima corresponded to 292 nm and 381 nm respectively. According to TEM results it was demonstrated that CdS quantum dots have a spherical shape, have no surface defects, and also have a diameter in the range from 3 to 9 nm, depending on the biological matrix. It was shown the absence of the negative effects of synthesized CdS nanoparticles on plant and animal cells. In addition, a technique for the functionalization of CdS quantum dots (P. ostreatus) using PEG and BSA has been developed.