ISSN 1023-1935, Russian Journal of Electrochemistry, 2012, Vol. 48, No. 4, pp. 457–466. © Pleiades Publishing, Ltd., 2012. Published in Russiam in Elektrokhimiya, 2012, Vol. 48, No. 4, pp. 502–512. 457 1. INTRODUCTION Fructose is a monosaccharide, the sweetest form of naturally occurring carbohydrate (CHO), and rela- tively abundant in nature. The increasing usage of fructose sweeteners in food and the association between high-fructose intake and the development of insulin resistance may be contributing factors to the escalating prevalence of metabolic syndrome and type 2 diabetes [1–3] therefore simple, sensitive and low- cost determination of fructose is of great significance to people’s health. Some methods have been devel- oped for the determination of fructose including spec- trophotometry, chromatography and electrochemical methods [4, 5]. The spectrophotometric and chro- matographic methods suffer from time-consuming, solvent-usage intensive or/and expensive (some require expensive devices and maintenance). There- fore, Electrochemical method is a very elegant in ana- lytical chemistry. In the electrochemical oxidation of fructose, the electrode material is clearly an important parameter where a high efficient electrocatalyst is needed. Hence, finding new electrode material for fructose determination is still of great interest. Over the past decade, one-dimensional (1D) inor- ganic–organic hybrid nanomaterials have received much interest because of their intriguing properties and potential applications in chemical or biochemical sensors, catalysis and nanodevices [6–13]. These hybrid materials based on the combination of organic and inorganic species exhibit the advantages over organic materials such as light weight, flexibility and good moldability and inorganic materials such as high strength, heat stability and chemical resistance [14, 15]. Such features of (1D) organic–inorganic hybrid nanomaterials maked them ideal building blocks for a new generation of electrochemical sen- sors. Recently, Gong, and co workers developed a hybrid of bimetallic inorganic–organic nano fibers (NFs) for the stripping assay of Hg(II) [16]. Decora- tion of organic nanowires with metal nanoparticle (NP) could be an attractive route to fabricate inor- ganic–organic hybrid nanomaterials without compro- mising the functions of the nanowires or nanoparticles [8]. The nanoparticles frequently display unusual physical and chemical properties depending upon their size, shape and stabilizing agents. Nanoparticles Immobilization of Nickel-Dipicolinic Acid onto a Glassy Carbon Electrode Modified with Bimetallic Au–Pt Inorganic–Organic Hybrid Nanocomposite: Application to Micromolar Detection of Fructose 1 M. B. Gholivand a, z and A. Azadbakht b a Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran b Department of Chemistry, Faculty of Basic Science, Islamic Azad University, Khorramabad Branch, Khorramabad, Iran Received February 28, 2011 Abstract—This work describes the electrochemical behavior of nickel-dipicolinic acid (Ni-DPA) film immobilized on the surface of bimetallic Au–Pt inorganic–organic hybrid nanocomposite glassy carbon electrode and its electrocatalytic activity toward the oxidation of fructose. The electrode possesses a three- dimensional (3D) porous network nano architecture, in which the bimetallic Au–Pt serving as metal nano- particle based microelectrode ensembles are distributed in the matrix of interlaced 3,3',5,5'-tetramethylben- zidine (TMB) organic nanofibers (NFs). The surface structure and composition of the sensor was character- ized by scanning electron microscopy (SEM). Electrocatalytic oxidation of fructose on the surface of modi- fied electrode was investigated with cyclic voltammetry and chronoamperometry methods and the results show that the Ni-DPA film displays excellent electrochemical catalytic activities towards fructose oxidation. The hydrodynamic amperometry at rotating modified electrode at constant potential versus reference elec- trode was used for detection of fructose. Under optimized conditions the calibration plots are linear in the concentration range 0.5 to 70 μM and detection limit was found to be 0.1 μM. Keywords: 3,3',5,5'-tetramethylbenzidine, fructose, nanocomposite electrodes, electrocatalysis DOI: 10.1134/S1023193512040064 1 The article is published in the original. z Corresponding author: m_b_gholivand@yahoo.com (M.B. Gholi- vand).