Electrooxidative grafting of amine-terminated dendrimers encapsulating nanoparticles for spatially controlled surface functionalization of indium tin oxide

Abstract

We report the electrochemical grafting of amine-terminated dendrimers encapsulating nanoparticles onto indium tin oxide (ITO) surfaces.

Enhanced Electrochemiluminescence of Luminol on Indium Tin Oxide Modified with Dendrimer‐Encapsulated Au Nanoparticles

“…Subsequently, we modified ITO electrode surfaces with the as‐synthesized Au DENs via electrooxidative grafting of the terminal amines of G6‐NH 2 PAMAM dendrimers encapsulating Au nanoparticles. As we reported in our recent studies, the synthesized Au DENs were electrochemically grafted onto ITO surfaces 10, 29. Specifically, we cycled the potential of the ITO electrodes three times between 1.20 and 1.75 V (vs. Ag/AgCl) in 10 µM Au DEN solutions containing 0.1 M LiClO 4 .…”

“…The modification of ITO electrodes was carried out with the as‐synthesized Au DENs using our previously reported electrochemical grafting method 10, 29. Briefly, an ITO electrode was ultrasonically cleaned in acetone, ethanol, and water, subsequently, and then it was dried with a N 2 blowing.…”

“…The other one is attachment of pre‐synthesized Au nanoparticles on electrodes with adhesive layers formed by silanization, self‐assembled monolayer (SAM) of thiolates, or layer‐by‐layer (LbL) assembly techniques 19, 24, 25. Recently, our group also reported electrochemical modification of electrode surfaces with amine‐terminated dendrimers encapsulating Au nanoparticles 26–29, which can be utilized for sensitive ECL‐based analyses 10. For example, we modified indium tin oxide (ITO) surfaces with dendrimer‐encapsulated Au nanoparticles (Au DENs) via electrooxidative grafting of amine terminals of the dendrimers onto ITO, and showed that the Au DEN‐modified ITO electrodes exhibited enhanced ECL emission of Ru(bpy) 3 2+ (bpy=2,2′‐bipyridyl) with tripropylamine (TPrA) co‐reactant even at lower applied potentials compared to bare ITOs 10, 29.…”

“…Recently, our group also reported electrochemical modification of electrode surfaces with amine‐terminated dendrimers encapsulating Au nanoparticles 26–29, which can be utilized for sensitive ECL‐based analyses 10. For example, we modified indium tin oxide (ITO) surfaces with dendrimer‐encapsulated Au nanoparticles (Au DENs) via electrooxidative grafting of amine terminals of the dendrimers onto ITO, and showed that the Au DEN‐modified ITO electrodes exhibited enhanced ECL emission of Ru(bpy) 3 2+ (bpy=2,2′‐bipyridyl) with tripropylamine (TPrA) co‐reactant even at lower applied potentials compared to bare ITOs 10, 29. However, we also reported that the Au DEN‐modified electrodes suffered from poor stability of Au DENs on electrode surfaces, which is consistent with previous studies reporting the poor stability of Au nanoparticle‐modified electrodes in oxidative potential regions, leading to unsteady ECL emissions of the Ru(bpy) 3 2+ /TPrA system 10, 17, 30.…”

Functionalization of Au surfaces with 4-(carboxymethyl)aniline and amine-terminated dendrimers for enhanced surface density of antibodies on immunosensor Au chips

“…[6][7][8] Of the strategies, electrografting methods have been demonstrated for the surface functionalization and subsequent immobilization of biological molecules on a variety of electrode surfaces such as carbon, metals, indium tin oxide (ITO), and diamond. [9][10][11][12][13] For example, the use of aryl diazonium cation has been suggested to perform a direct electrochemical grafting at the surface of conducting electrodes. 3,14,15 Recently, our group also reported the electrochemical grafting of amine-terminated dendrimers on electrode surfaces.…”