title: Label-free detection of proteins from self-assembled protein-silver nanoparticle structures using surface-enhanced Raman scattering.
abstract: Proteins are one of the most versatile groups of molecules with vital functional roles in living systems. Their enormous diversity and structural flexibility make the detection of these molecules a challenging task. A simple and sensitive label-free protein detection method based on assembly of proteins and colloidal silver nanoparticles (AgNPs) on surfaces and surface-enhanced Raman scattering (SERS) is reported. The SERS spectra from the assembled AgNP/protein films show excellent reproducibility and high quality regardless of the proteins' charge status and size. A detection limit down to 0.5 μg/mL for three acidic proteins; BSA, catalase and pepsin, and three basic proteins; cytochrome c, avidin and lysozyme, is easily achieved. The minimum improvement in detection limit is more than 1 order of magnitude compared to the previously reported detection limits using the technique and the approach has the potential for label-free protein detection and identification.
authors.affiliation: Department of Genetics and Bioengineering, Yeditepe University, Kayışdağı/Kadıköy, Istanbul 34755, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kahraman
authors.forename: Ilknur
authors.initials: I
authors.lastname: Sur
authors.forename: Mustafa
authors.initials: M
authors.lastname: Culha
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D053768:Metal Nanoparticles / Q000737:chemistry*; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D015203:Reproducibility of Results; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D013535:Suspensions
chemical_list: D011506:Proteins; D013535:Suspensions; D012834:Silver