Green synthesis characterization and evaluation of tea leaf derived cds quantum dots for optical properties and anticancer activities

Abstract

In the current scenario, nanoscience and nanotechnology involves in diverse applications such as medicine, textiles, electronic, agriculture and mechanical industries. Green technology for nanoparticles synthesis is considered to be of great significance in biomedical applications. Recently, low dimensional semiconductor cadmium sulfide (CdS) quantum dots (QDs) have raised great attention due to their optical properties and wide usage in biomedical studies. QDs has powerful probes for fluorescence imaging due to its several advantages, it has been developed for additional applications such as single-protein tracking, detection of diseases, intracellular reporting and disease detection. The recent research has emphasized to produce biocompatible QDs using green synthesis approaches. The present work focuses on the simple green synthesis route for CdS QDs production using young and matured tea leaves (mother leaf) as bio-surfactant that are a waste product of the tea leaf industry and not suitable for drinking. The physicochemical characterization of synthesized CdS QDs is carried out using different techniques such as FTIR, EDX, XRD, PL and HR-TEM. The young tea leaves mediated CdS QDs (Green CdS QDs) exhibits the optical absorption at 410 - 420 nm and fluorescence emission was found to be at 670 nm. SEM image of Green CdS QDs shows the spherical morphology and EDX results confirms the presence of inorganic materials (Cd, S and O). This green CdS QDs shows particle size ranges from 3-5 nm by HR-TEM analysis. Similarly, matured tea leaves (MT-CdS QDs) shows optical absorption spectra at 410 nm and fluorescence emission was found to be 670 nm. Surprisingly, MT-CdS QDs also shows particle size in the quantum region (2 4 nm). newline