title: Magnetic graphene oxide-supported hemin as peroxidase probe for sensitive detection of thiols in extracts of cancer cells.
abstract: Magnetic graphene oxide (GO)-hemin probes containing disulfide bonds are simply and effectively synthesized through amide reaction to covalently link magnetic particles to GO surface and π-π stacking interaction between hemin and GO to immobilize hemin on GO. Based on the strong nucleophilicity of sulfhydry, we have developed a colorimetric detection system for thiols by using glutathione (GSH) as a model analyte. Upon the introduction of GSH to the fabricated magnetic particle (MP)-GO-hemin probes, the disulfides can be readily reduced by thiols, resulting in the release of GO-hemin hybrids to solution. Due to the existence of hemin on GO surface, the released GO-hemin that has the intrinsic peroxidase-like activity can catalyze the oxidation of ABTS(2-) by H2O2 to form the colored radical product ABTS(·-). A broad linear dynamic range of 10(-10) M to 10(-6) M GSH is achieved with a detection limit of 8.2×10(-11) M (3σ). Moreover, the new probe is successfully applied to the detection of non-protein thiols and protein thiols in the extracts of Ramos cells, which shows favorable correlationship with the results obtained by electrochemical method. In addition, the MP-GO-hemin probe can detect non-protein thiols in Ramos extracts as low as 500 cells. In this assay, the prepared MP-GO-hemin conjugates are thoroughly characterized by SEM, AFM, UV-Vis, FT-IR, and Raman spectroscopy.
authors.affiliation: Shandong Provincial Key Laboratory of Detection Technology of Tumor Markers, School of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, China; Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China. Electronic address: bisai11@126.com.
authors.forename: Sai
authors.initials: S
authors.lastname: Bi
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Jia
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
authors.forename: Peng
authors.initials: P
authors.lastname: He
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D003124:Colorimetry / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D006427:Hemin / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D059346:Magnets / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D009369:Neoplasms / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D009195:Peroxidase / Q000737:chemistry; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds / Q000032:analysis*
chemical_list: D010087:Oxides; D013438:Sulfhydryl Compounds; D006427:Hemin; D006108:Graphite; D009195:Peroxidase
keywords: Artificial enzyme mimetic; Colorimetry; Graphene oxide (GO); Probe; Thiols