Mentha arvensis mediated green synthesis of platinum doped TiO2 nanocomposite for enhanced anti-cancer and photocatalytic degradation activity: Insights from molecular docking and DFT studies

Abstract

A green synthetic route has been developed for the synthesis of Pt doped Titanium dioxide nanocomposite (Pt/TiO2). Mentha arvensis (Mint) leaves extract has been used as a reducing agent to get Pt/TiO2 nanocomposite. Spectroscopic, morphological analysis confirms the doping of Pt to TiO2. High-resolution XPS shows the presence of Ti4+ and Ti3+ mixed/dual oxidation state of Ti in the nanocomposite. TiO2 and Pt/TiO2 materials have been used to evaluate its anti-cancer activity against MCF-7 (human breast), HCT 116 (Colon cancer) and HepG2 (hepatocellular carcinoma) cell lines. The Pt/TiO2 showed enhanced anti-cancer activity compared to TiO2 and showed 4.71 ± 0.81, 10.54 ± 0.58 and 7.16 ± 0.34 IC50 values against MCF-7, HCT 116 and HepG2, respectively. Pt/TiO2 were subjected for inhibition efficiency towards VEGFR-2 and HER-2 kinase enzymes and observed 0.491 ± 0.72 and 0.071 ± 0.13 IC50 values, respectively. The obtained IC50 values are comparable with reference drugs under study. Molecular docking studies support and confirm the formation of hydrogen bonding between Pt/TiO2 and VEGFR-2 and HER-2 proteins. Additionally for the first time, photocatalytic studies on the degradation of doxorubicin (DOX); an ant-cancer drug has been studied in detail using Pt/TiO2. Pt/TiO2 exhibited enhanced photocatalytic efficiency and was able to degrade 88% DOX under visible light. DFT studies show the bandgap of TiO2 decreased to 2.71 eV upon addition of Pt, which is in close agreement with obtained experimental results. The degradation mechanism has been predicted in support of LC-MS studies. So, Pt/TiO2 could serve as a material with dual applications in the field of environmental remediation and the medical field.