Vanadium-Incorporated Mesoporous Silica as Oxidase Mimic for Colorimetric Dopamine Detection and Anticancer Activity

The intriguing features of artificial enzymes made nanozymes attractive in the field of biosensing and biomedical. Here, vanadium-incorporated dendritic mesoporous silica (VMSN) as an oxidase mimicking nanozyme was utilized as a sensitive and selective colorimetric biosensor to detect dopamine (DA) and treat cancer cells. The nanozyme was successfully fabricated through the in-situ incorporation of vanadium ions in the silica framework via a simple sol-gel method using CTAB and mesitylene. The excellent oxidase-like activity of VMSN was monitored by the oxidation of TMB. The kinetics, mechanism of the catalytic reaction and the effect of temperature, pH, and concentration on oxidase-like activity were investigated thoroughly and further, based on the oxidase-like activity, a fast and sensitive colorimetric sensing of dopamine developed with a LOD of 0.0021 mu M and a linear range of 0-50 mu M. The proposed colorimetric method was successfully used to determine DA concentration in commercially available dopamine hydrochloride injection.VMSN was further modified with folic acid and utilized against cancer cells in vitro. Neuroblastoma cells (SHSY-5Y) show ROS generated by VMSN in the presence of oxygen, leading to enhanced cytotoxicity detrimental for SHSY-5Y cells.