title: A wide range optical pH sensor for living cells using Au@Ag nanoparticles functionalized carbon nanotubes based on SERS signals.
abstract: p-Aminothiophenol (pATP) functionalized multi-walled carbon nanotubes (MWCNTs) have been demonstrated as an efficient pH sensor for living cells. The proposed sensor employs gold/silver core-shell nanoparticles (Au@Ag NPs) functionalized MWCNTs hybrid structure as the surface-enhanced Raman scattering (SERS) substrate and pATP molecules as the SERS reporters, which possess a pH-dependent SERS performance. By using MWCNTs as the substrate to be in a state of aggregation, the pH sensing range could be extended to pH 3.0∼14.0, which is much wider than that using unaggregated Au@Ag NPs without MWCNTs. Furthermore, the pH-sensitive performance was well retained in living cells with a low cytotoxicity. The developed SERS-active MWCNTs-based nanocomposite is expected to be an efficient intracellular pH sensor for bio-applications.
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing, 210096, Jiangsu, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Chen
authors.forename: Zhuyuan
authors.initials: Z
authors.lastname: Wang
authors.forename: Shenfei
authors.initials: S
authors.lastname: Zong
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Dan
authors.initials: D
authors.lastname: Zhu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhong
authors.forename: Yiping
authors.initials: Y
authors.lastname: Cui
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002470:Cell Survival; D002477:Cells / Q000737:chemistry* / Q000166:cytology; D006046:Gold / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*
chemical_list: D037742:Nanotubes, Carbon; D012834:Silver; D006046:Gold