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

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 N-2 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.