title: On-line enhancement and separation of nanoparticles using capillary electrophoresis.
abstract: We describe a rapid, simple, and highly efficient capillary electrophoresis (CE)-based method for the analysis of nanoparticles (NPs). In this study, we used the reversed electrode polarity stacking mode (REPSM) of CE to assess the feasibility of enhancing the detection of Au NPs and Au/Ag NPs, optimizing parameters such as the length of time for which the REPSM was applied, the concentrations of the buffer and the sodium dodecylsulfate (SDS) surfactant, and the pH. Under the optimized on-line enhancement conditions [buffer: SDS (40 mM) and 3-cyclohexylamino-1-propanesulfonic acid (CAPS; 10 mM) at pH 10.0; applied voltage: 20 kV; REPSM applied for 24s], the detection limits of the Au NPs and Au/Ag NPs increased by ca. 30- and 140-fold, respectively. In addition, when the NPs were subjected to on-line enhancement and separation by CE using diode array detection (DAD), this approach allowed chemical characterization of the NP species. Our results suggest that such CE analyses will be useful for accelerating the rates of fabrication and characterization of future nanomaterials.
authors.affiliation: Department of Biomedical Engineering and Environmental Sciences, National Tsing-Hua University, Hsinchu 30013, Taiwan.
authors.forename: Kuei-Hua
authors.initials: KH
authors.lastname: Lin
authors.forename: Tieh-Chi
authors.initials: TC
authors.lastname: Chu
authors.forename: Fu-Ken
authors.initials: FK
authors.lastname: Liu
mesh_terms: D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002021:Buffers