22 research outputs found
Synthesis and Characterization of GoldâEpoxy Nanocomposites by Visible Light Photoinduced Electron Transfer and Cationic Polymerization Processes
Surface Enhanced Infrared Absorption Spectroscopy Studies of DMAP Adsorption on Gold Surfaces
Effect of Areal Chain Density on the Location of Polymer-Modified Gold Nanoparticles in a Block Copolymer Template
Characterization of Poly(ethylene oxide)-Capped Gold Nanoparticles in Water by Means of Transmission Electron Microscopy, Thermogravimetric Analysis, Mass Density, and Small Angle Scattering
Enhanced Electrochemiluminescence and Charge Transport Through Films of Metallopolymer-Gold Nanoparticle Composites
peer-reviewedWater-soluble 4-(dimethylamino) pyridine (DMAP) stabilized gold nanoparticles (DMAP-AuNP) were synthesized by ligand exchange and phase transfer (toluene/water). The DMAP-AuNPs are positively charged with the core diameter of 4 +/- 1 nm. Metallopolymer-gold nanocomposites were prepared by mixing gold nanoparticles and [Ru(bpy)(2)PVP(10)](ClO(4))(2), in water at different mole ratios: bpy is 2,2'-bipyridyl and PVP is poly (4-vinylpyridine). The photoluminescence emission intensity of the metallopolymer decreases with increasing AuNP loading and approximately 57% of the emission intensity is quenched when the Au NP:Ru mole ratio is 14.8 x 10(-2). The rate or homogeneous charge transfer through thin layers of the nanocomposite deposited oil glassy carbon electrodes increases with increasing nanoparticle loading. The homogeneous charge transport diffusion coefficient, D(CT)., for the composite (AuNP:Ru mole ratio 13.2 x 10(-2)) is (2.8 +/- 0.8) X 10(-11) cm(-2) s(-1) and is approximately 3-fold higher than that found for the pure metallopolymer. Significantly, despite the ability of the metal nanoparticles to quench the ruthenium-based emission, the electrochemiluminescence of the nanocomposite with a AuNP:Ru mole ratio of 4.95 x 10(-2) is approximately three times more intense than the parent metallopolymer. This enhancement arises from the increased rate of charge transport that leads to it greater number of excited states per unit time while minimizing lie quenching effects. The implications of these findings for the design of electrochemiluminescent sensors are discussed.PUBLISHEDpeer-reviewe