title: Cancer cell detection and therapeutics using peroxidase-active nanohybrid of gold nanoparticle-loaded mesoporous silica-coated graphene.
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 (GSF@AuNPs) 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 GSF@AuNPs 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 GSF@AuNPs 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.
authors.affiliation: †Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.
authors.forename: Swarup Kumar
authors.initials: SK
authors.lastname: Maji
authors.affiliation: †Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.
authors.forename: Amal Kumar
authors.initials: AK
authors.lastname: Mandal
authors.affiliation: †Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.
authors.forename: Kim Truc
authors.initials: KT
authors.lastname: Nguyen
authors.affiliation: †Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.
authors.forename: Parijat
authors.initials: P
authors.lastname: Borah
authors.affiliation: †Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore.|‡School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D001560:Benzidines / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival; D003124:Colorimetry; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D057809:HEK293 Cells; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000175:diagnosis* / Q000628:therapy*; D010084:Oxidation-Reduction; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D001560:Benzidines; C021758:3,3',5,5'-tetramethylbenzidine; D006046:Gold; D012822:Silicon Dioxide; D006108:Graphite; D006735:Horseradish Peroxidase
keywords: cancer cell detection; gold nanoparticles; graphene; peroxidase activity; therapeutics