Study of biosynthesis of CdS Quantum dot (QD) by methanolic extracts of Physalis peruviana L.

DNA methylation detection by a novel fluorimetric nanobiosensor for early cancer diagnosis Quantum dots as a fluorescent probe are applied for cell biology, DNA transformation, biomedical imaging and cancer therapy. Biological based synthesis of nanoparticles would be more efficient and environment friendly rather than chemical approaches. In the present study, quantum dots have been synthesized through leaf methanolic extracts. The obtained results by UV-vis spectroscopy, TEM, FT-IR and fluorescence spectroscopy showed the presence of synthesized CdS quantum dots. Yellow and orange colors of obtained solution was also indicated the successful synthesis of CdS quantum dots. The maximum UV-Vis spectrum absorption of quantum dots was observed at 410 nm. Results of fluorescence analysis also showed that emission bands were at 475, 490 and 675 respectively which indicated the synthesis of different CdS quantum dots in different pH values. Obtained nanoparticle were spherical and at the range between 2-10 nm according to TEM analysis. FT-IR analysis also showed that the proteins, leucine and lysine amino acids, phenols and other functional groups present in physalis extracts would be determining factors for reducing CdS ions and converting them to quantum dots.