title: Highly narrow nanogap-containing Au@Au core-shell SERS nanoparticles: size-dependent Raman enhancement and applications in cancer cell imaging.
abstract: Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on the surface of cancer cells. First, plasmonic nanostructures are made of gold nanoparticles (∼15 nm) coated with gold shells, between which a highly narrow and uniform nanogap (∼1.1 nm) is formed owing to polyA anchored on the Au cores. The well controlled distribution of Raman reporter molecules, such as 4,4'-dipyridyl (44DP) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), are readily encoded in the nanogap and can generate strong, reproducible SERS signals. In addition, we have investigated the size-dependent SERS activity of GCNPs and found that with the same laser wavelength, the Raman enhancement discriminated between particle sizes. The maximum Raman enhancement was achieved at a certain threshold of particle size (∼76 nm). High narrow nanogap-containing Au@Au core-shell SERS tags (GCTs) were prepared via the functionalization of hyaluronic acid (HA) on GCNPs, which recognized the CD44 receptor, a tumor-associated surface biomarker. And it was shown that GCTs have a good targeting ability to tumour cells and promising prospects for multiplex biomarker detection.
authors.affiliation: School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. hdn_nercn@163.com.
authors.forename: Chongya
authors.initials: C
authors.lastname: Hu
authors.affiliation: Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Jianlei
authors.initials: J
authors.lastname: Shen
authors.affiliation: National Engineering Research Center for Nanotechnology, Shanghai 200241, China. yjsinap@163.com and Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yan
authors.affiliation: National Engineering Research Center for Nanotechnology, Shanghai 200241, China. yjsinap@163.com and Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Qin
authors.affiliation: National Engineering Research Center for Nanotechnology, Shanghai 200241, China. yjsinap@163.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: Chemistry Department, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
authors.forename: Ali
authors.initials: A
authors.lastname: Aldalbahi
authors.affiliation: Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zuo
authors.affiliation: Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Shiping
authors.initials: S
authors.lastname: Song
authors.affiliation: Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Chunhai
authors.initials: C
authors.lastname: Fan
authors.affiliation: School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. hdn_nercn@163.com and National Engineering Research Center for Nanotechnology, Shanghai 200241, China. yjsinap@163.com.
authors.forename: Dannong
authors.initials: D
authors.lastname: He
mesh_terms: D045744:Cell Line, Tumor; D004136:Dinitrobenzenes / Q000737:chemistry / Q000494:pharmacology; D006046:Gold / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D009363:Neoplasm Proteins / Q000378:metabolism; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D011725:Pyridines / Q000737:chemistry / Q000494:pharmacology; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: C497483:CD44 protein, human; D004136:Dinitrobenzenes; D018960:Hyaluronan Receptors; D009363:Neoplasm Proteins; D011725:Pyridines; D006046:Gold; C010936:2,4-dinitrothiocyanatobenzene; C034306:4,4'-bipyridyl