title: Rapid visual detection of quaternary ammonium surfactants using citrate-capped silver nanoparticles (Ag NPs) based on hydrophobic effect.
abstract: In this work, a rapid, sensitive and low-cost colorimetric method for detection of quaternary ammonium surfactants using citrate-capped silver nanoparticles (Ag NPs) was developed. The quaternary ammonium surfactants induce the aggregation of Ag NPs through the hydrophobic effect, which is a novel aggregation mechanism of Ag NPs. The addition of cationic surfactant results in color change of Ag NPs solution from yellow to red and finally to colorless, which is due to the broadening of the surface plasmon band. The color change was monitored using a UV-vis spectrophotometer. The LOD of different cationic surfactants was in the range of 0.5-5 µM. More importantly, this detection method was successfully utilized to the disinfectant residual sample.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Li-Qing
authors.initials: LQ
authors.lastname: Zheng
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Yu
authors.forename: Jing-Juan
authors.initials: JJ
authors.lastname: Xu
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Chen
mesh_terms: D002951:Citrates / Q000737:chemistry*; D004202:Disinfectants / Q000032:analysis*; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000032:analysis*
chemical_list: D002951:Citrates; D004202:Disinfectants; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; D012834:Silver
keywords: Cationic surfactants; Citrate-capped silver nanoparticles; Colorimetric detection; Hydrophobic effect