title: Highly sensitive and specific detection of E. coli by a SERS nanobiosensor chip utilizing metallic nanosculptured thin films.
abstract: A nanobiosensor chip, utilizing surface enhanced Raman spectroscopy (SERS) on nanosculptured thin films (nSTFs) of silver, was shown to detect Escherichia coli (E. coli) bacteria down to the concentration level of a single bacterium. The sensor utilizes highly enhanced plasmonic nSTFs of silver on a silicon platform for the enhancement of Raman bands as checked with adsorbed 4-aminothiophenol molecules. T-4 bacteriophages were immobilized on the aforementioned surface of the chip for the specific capture of target E. coli bacteria. To demonstrate that no significant non-specific immobilization of other bacteria occurs, three different, additional bacterial strains, Chromobacterium violaceum, Paracoccus denitrificans and Pseudomonas aeruginosa were used. Furthermore, experiments performed on an additional strain of E. coli to address the specificity and reusability of the sensor showed that the sensor operates for different strains of E. coli and is reusable. Time resolved phase contrast microscopy of the E. coli-T4 bacteriophage chip was performed to study its interaction with bacteria over time. Results showed that the present sensor performs a fast, accurate and stable detection of E. coli with ultra-small concentrations of bacteria down to the level of a single bacterium in 10 μl volume of the sample.
authors.affiliation: Department of Electro optic Engineering, Ben Gurion University of the Negev, Beer Sheva 84105, Israel. sachinchitransh@gmail.com.
authors.forename: Sachin K
authors.initials: SK
authors.lastname: Srivastava
authors.forename: Hilla Ben
authors.initials: HB
authors.lastname: Hamo
authors.forename: Ariel
authors.initials: A
authors.lastname: Kushmaro
authors.forename: Robert S
authors.initials: RS
authors.lastname: Marks
authors.forename: Christoph
authors.initials: C
authors.lastname: Grüner
authors.forename: Bernd
authors.initials: B
authors.lastname: Rauschenbach
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Abdulhalim
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D017122:Bacteriophage T4 / Q000302:isolation & purification; D004867:Equipment Design; D004926:Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D013438:Sulfhydryl Compounds; D012834:Silver; C064316:4-aminothiophenol