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

Abstract

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 μM and a linear range of 0–50 μM. 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.

Facile preparation of V2C@VOx nanosheets with excellent multi-enzyme activity and their colorimetric sensing application

“…Firstly, a classical NBT was used as the chromogenic substrate to verify the superoxide dismutase-like activity of V 2 C@VO x nanosheets. 21 As we all know, O 2 ˙ − is generated by riboflavin with illumination, reducing nitro-tetrazolium blue chloride to a blue formazan product. 21 However, superoxide dismutase activity can disrupt the formation of the blue formazan product.…”

“…21 As we all know, O 2 ˙ − is generated by riboflavin with illumination, reducing nitro-tetrazolium blue chloride to a blue formazan product. 21 However, superoxide dismutase activity can disrupt the formation of the blue formazan product. From Fig.…”

“…It is well-known that TA can capture ˙ OH to form 2-hydroxyterephthalic acid (HTA) with strong fluorescence. 21 In order to demonstrate the catalytic mechanism of peroxidase-like activity of V 2 C@VO x nanosheets, the fluorescence spectra of V 2 C@VO, TA, V 2 C@VO x /TA, V 2 C@VO x /TA/H 2 O 2 incubated with NaAc–HAc buffer (pH 4.0, 0.2 M) at 40 °C for 3 h were obtained. From Fig.…”

“…The classical NBT colorimetric method was used to investigate the superoxide dismutase-like activity of V 2 C@VO x nanosheets. 21 The NBT (112.5 mM), methionine (1.95 mM), riboflavin (3 mM), Na 2 EDTA (15 mM) and different concentrations of V 2 C@VO x nanosheets were added to phosphate buffered saline (pH = 7.8, 0.2 M) solution. The mixed solution was performed under light for 5 min.…”

“…Firstly, a classical NBT was used as the chromogenic substrate to verify the superoxide dismutase-like activity of V 2 C@VO x nanosheets. 21 As we all know, O 2…”