title: Selective and sensitive detection of intracellular O2(•-) using Au NPs/cytochrome c as SERS nanosensors.
abstract: A novel surface-enhanced Raman scattering (SERS) nanosensor was developed by modifying oxidized cytochrome c (Cyt c) on gold nanoparticles (Au NPs) for the sensitive and selective determination of intracellular superoxide anion radical (O2(•-)). On the basis of the differences in the SERS spectra between the oxidized and reduced form of Cyt c, this nanosensor could be employed to investigate O2(•-) concentration by measuring the SERS spectra of the reduced Cyt c. Using this SERS nanosensor, a detection limit of 1.0 × 10(-8) M for O2(•-) could be attained. Additionally, the selectivity of the SERS nanosensor for O2(•-) was examined, showing that other reactive oxygen species (ROS) and biologically relevant species did not influence the detection of O2(•-). More importantly, the nanosensor could be delivered to the living HeLa and normal human liver cells and permitted the concentration of O2(•-) to be monitored in real time and in a noninvasive manner, which indicates that this nanosensor will be suitable for the qualitative and quantitative analysis of O2(•-) in biosystems, thus leading to a greater understanding of oxidative-stress-related diseases at a cellular level.
authors.affiliation: State Key Laboratory of Bioreactor Engineering and Department of Chemistry, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Qu
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Li
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Qin
authors.forename: Jin
authors.initials: J
authors.lastname: Mu
authors.forename: John S
authors.initials: JS
authors.lastname: Fossey
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Long
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D042541:Intracellular Space / Q000737:chemistry*; D008099:Liver / Q000166:cytology; D053768:Metal Nanoparticles / Q000737:chemistry; D008958:Models, Molecular; D036103:Nanotechnology / Q000379:methods*; D011487:Protein Conformation; D013059:Spectrum Analysis, Raman; D013481:Superoxides / Q000032:analysis*
chemical_list: D013481:Superoxides; D006046:Gold; D045304:Cytochromes c