title: Sensitive and selective SERS probe for trivalent chromium detection using citrate attached gold nanoparticles.
abstract: In this article, we have demonstrated a sensitive and selective surface enhanced Raman spectroscopy (SERS) probe, based on citrate-capped gold nanoparticles (AuNPs), for trivalent chromium (Cr(3+)) detection. After introducing Tween 20 to a solution of citrate-capped AuNPs, the as-prepared Tween 20/citrate-AuNP probe could recognize Cr(3+) at a 50 × 10(-9) M level in an aqueous medium at a pH of 6.0. Tween 20 can stabilize the citrate-capped AuNPs against conditions of high ionic strength. Due to the chelation between Cr(3+) and citrate ions, AuNPs undergo aggregation. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity through electromagnetic (EM) field enhancements. A detailed mechanism for tremendous SERS intensity change had been discussed. The selectivity of this system toward Cr(3+) was 400-fold, remarkably greater than other metal ions.
authors.affiliation: Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Ye
authors.forename: Honglin
authors.initials: H
authors.lastname: Liu
authors.forename: Liangbao
authors.initials: L
authors.lastname: Yang
authors.forename: Jinhuai
authors.initials: J
authors.lastname: Liu
mesh_terms: D002857:Chromium / Q000032:analysis*; D019343:Citric Acid / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; D019343:Citric Acid; D006046:Gold