Abstract
Development of efficient artificial enzymes is an emerging field in nanobiotechnology, since these artificial enzymes could overcome serious disadvantages of natural enzymes. In this work, a new nanostructured hybrid was developed as a mimetic enzyme for in vitro detection and therapeutic treatment of cancer cells. The hybrid ([email protected]) was prepared by the immobilization of gold nanoparticles (AuNPs) on mesoporous silica-coated nanosized reduced graphene oxide conjugated with folic acid, a cancer cell-targeting ligand. The [email protected] hybrid showed unprecedented peroxidase-like activity, monitored by catalytic oxidation of a typical peroxidase substrate, 3,3′,5,5′-tetramethylbenzidine (TMB), in the presence of H2O2. On basis of this peroxidase activity, the hybrid was utilized as a selective, quantitative, and fast colorimetric detection probe for cancer cells. Finally, the hybrid as a mimetic enzyme was employed for H2O2- and ascorbic acid (AA)-mediated therapeutics of cancer cells. In vitro experiments using human cervical cancer cells (HeLa cells) exhibited the formation of reactive oxygen species (OH• radical) in the presence of peroxidase-mimic [email protected] with either exogenous H2O2 or endogenous H2O2 generated from AA, leading to an enhanced cytotoxicity to HeLa cells. In the case of normal cells (human embryonic kidney HEK 293 cells), the treatment with the hybrid and H2O2 or AA showed no obvious damage, proving selective killing effect of the hybrid to cancer cells.
Funding Information
  • Nanyang Technological University (1123510003)
  • National Research Foundation-Prime Minister's office, Republic of Singapore (NRF2009NRF-RF001-015)
  • International Institute for Nanotechnology, Northwestern University
  • Agency for Science, Technology and Research (1123510003)

This publication has 50 references indexed in Scilit: