title: Label-free and direct protein detection on 3D plasmonic nanovoid structures using surface-enhanced Raman scattering.
abstract: In this paper we use surface-enhanced Raman spectroscopy (SERS) on 3D metallic structures for label-free detection and characterization of proteins of interest at low concentrations. The substrates are prepared via nanopatterning with latex nano/microparticles and Cr and Ag sputtering, yielding stable, tunable, and mechanically flexible plasmonic structures. The nanovoids generate a SERS signal of the proteins of interest that is background free and independent of the protein charge. Concentrations as low as 0.05 μg mL(-1) could be detected for 4 different proteins. The proteins also exhibit significantly different SERS spectra on these substrates, which is an important feature for future label-free direct detection schemes.
authors.affiliation: Department of Chemistry, Faculty of Arts and Sciences, University of Gaziantep, 27310 Sehitkamil, Gaziantep, Turkey. Electronic address: mkahraman@gantep.edu.tr.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kahraman
authors.affiliation: Center for Biophotonics, University of California Davis, Sacramento, CA 95817, USA; Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, CA 95817, USA. Electronic address: swachsmann@ucdavis.edu.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wachsmann-Hogiu
mesh_terms: D000818:Animals; D002417:Cattle; D002857:Chromium / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008968:Molecular Conformation; D011506:Proteins / Q000032:analysis* / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D011506:Proteins; D002857:Chromium; D012834:Silver
keywords: Label-free; Nanobowls; Protein detection; Surface enhanced Raman spectroscopy