Preparation, Characterization, and Electrocatalytic Activity of Surface Anchored, Prussian Blue Containing Starburst PAMAM Dendrimers on Gold Electrodes

Abstract

Gold bead electrodes were modified with submonolayers of 3-mercaptopropionic acid or 2-aminoethanethiol and further reacted with poly(amidoamine) (PAMAM) dendrimers (generation 4.0 and 3.5, respectively) to obtain films on which Prussian Blue (PB) was later absorbed to afford mixed and stable electrocatalytic layers. Experiments carried out with these novel materials not only showed an improved surface coverage of PB on the dendrimer modified electrodes as compared to PB modified gold electrodes prepared under acidic conditions, but also showed an increased stability at neutral pH values for one of the dendrimer containing substrates where the PB film on a bare gold electrode is simply not formed. The dendrimer modified electrodes were also tested as electrocatalytic substrates for the electroxidation of L(+)-ascorbic acid (AA), and it was found that their sensitivity as well as the corresponding detection limits were improved as compared to the voltammetric response of a Au-PB modified electrode. On the basis of UV-visible (UV-vis) spectroscopy and electrochemical experiments, it is suggested that the PB molecules are located within the dendritic structure of the surface attached PAMAM dendrimers.

Amperometric Detection of H2O2 Using Gold Electrodes Modified with Starburst PAMAM Dendrimers and Prussian Blue

“…Analytical grade Ru(NH 3 ) 6 The electrochemical experiments reported in this work were performed using a BAS Epsilon potentiostat from Bioanalytical Systems, Inc. The cyclic voltammetry (CV) and amperometric experiments were performed at 298 K in a 10-mL BAS cell equipped with a gold-bead working electrode, a platinum counter electrode, and a Ag/AgCl (3 M NaCl) reference electrode.…”

“…Electrodes covalently modified with PAMAM dendrimers (generation 4.0 and 3.5) have been found to support films of PB with improved surface coverage compared to simple PB-modified gold electrodes, which are prepared under acidic conditions. Also, good stability at neutral pH values was obtained with PB supported by poly(amidoamine) (PAMAM) dendrimer, generation 4.0, whereas no PB film forms on a bare gold electrode under these conditions [6]. Since dendrimers resemble covalent micelles characterized by well defined cavities that serve as endoreceptor sites and also by terminal groups that provide specific solubility and reactivity characteristics [7,8], they are well suited to modify electrode surfaces and to support charge-transfer mediators.…”

“…Since dendrimers resemble covalent micelles characterized by well defined cavities that serve as endoreceptor sites and also by terminal groups that provide specific solubility and reactivity characteristics [7,8], they are well suited to modify electrode surfaces and to support charge-transfer mediators. Enhancing the hydrophobic nature of the electrode-solution interface can stabilize and concentrate a mediator such as PB [6], thus improving the kinetics and selectivity of specific electrochemical reactions [9,10]. The purpose of this paper is to compare the preparation and performance of covalently modified gold electrodes with those of bare gold electrodes coated electrostatically with various generations of PAMAM dendrimers loaded with PB.…”

Assembly and electroanalytical performance of Prussian blue/polypyrrole composite nanoparticles synthesized by the reverse micelle method

“…Nanomaterials exhibit unique optical, electronic and catalytic properties, and have promising applications in various areas [5,6]. Owing to their large surface-to-volume ratio and increased surface activity, nanosized PB particles have received increasing attention in the field of electroanalysis and biosensors [7,8]. Qian and Yang coated PB onto SiO 2 nanoparticles and carbon nanotubes by electrostatic interaction [9].…”

Preparation and study of cellulose acetate membranes modified with linear polymers covalently bonded to Starburst polyamidoamine dendrimers

“…15,16 Because of the unique chemical and structural properties of dendrimers, a number of potential applications have been proposed, some of which include the design and preparation of chemical sensors, [17][18][19] the dendritic encapsulation of transition-metal ions, [20][21][22][23] the controlled release of small compounds, 24 and their use in membrane chemistry, 25,26 among many others. 27,28 In the area of membrane construction with dendrimers, Crooks and coworkers [29][30][31] have developed novel polymeric composite films formed from multilayers of amine-terminated polyamidoamine (PAMAM) dendrimers and poly(maleic anhydride)-c-(methyl vinyl ether) (Gantrez) grafted onto Aucoated Si wafers. Because of the protonation properties of the amine surface groups of the surface anchored PAMAM dendrimers, these composite materials exhibited pH-switchable permeation selectivity for anionic and cationic redox-active probe molecules.…”