Synthesis of mesoporous silica oxide/C-dot complex (meso-SiO₂/C-dots) using pyrolysed rice husk and its application in bioimaging

Abstract

Due to the abundance of silica and carbon in rice (Oryza sativa) husk (RH), we exploited it for the synthesis of a mesoporous silica oxide micro-particles (meso-SiO2)/C-dot complex for biological imaging using a novel hot injection method commonly used for semiconductor quantum dots. Carbon dots (C-dots) with a high degree of green fluorescence were observed under UV-light they were found to be embedded to a significant extent in meso-SiO2 as confirmed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The mesoporous nature of the complex was confirmed using N2 adsorption–desorption measurements. Surface functionalization was studied using Fourier transform infrared spectroscopy (FTIR). The synthesized meso-SiO2/C-dots complex was used for labeling yeast cells since the fungi closely represents eukaryotic organisms. Furthermore, the meso-SiO2/C-dot complex was found to be highly bio-compatible for Vero cells. This study might help in the further utilization of the complex for the theranostic application of simultaneous cellular imaging and drug delivery.