J. Electrochem. Sci. Technol., 2018, 9(3), 169-175 - 169 - Chitosan-Cu-salen/Carbon Nano-Composite Based Electrode for the Enzyme-less Electrochemical Sensing of Hydrogen Peroxide Harishchandra Digambar Jirimali 1,2 *, Duraisamy Saravanakumar 1,3 , and Woonsup Shin 1 * Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742 Republic of Korea School of Chemical Sciences, North Maharashtra University, Jalgaon (MS) 425001 India Department of Chemistry, School of Advanced Sciences, VIT University, Vellore-632014, India ABSTRACT Cu-Salen complex was prepared and attached into chitosan (Cs) polymer backbone. Nanocomposite of the synthesized polymer was prepared with functionalized carbon nano-particles (Cs-Cu-sal/C) to modify the electrode surface. The surface morphology of (Cs-Cu-sal/C) nanocomposite film showed a homogeneous distribution of carbon nanoparticles within the polymeric matrix. The cyclic voltammogram of the modified electrode exhibited a redox behavior at -0.1 V vs. Ag/AgCl (3 M KCl) in 0.1 M PB (pH 7) and showed an excellent hydrogen peroxide reduction activity. The Cs-Cu-sal/C electrode displays a linear response from 5×10 to 5×10 M, with a correlation coefficient of 0.993 and detection limit of 0.9 μM (at S/N = 3). The sensitivity of the electrode was found to be 0.356 μA μM cm . Keywords : Electrochemical sensor, Hydrogen peroxide, Chitosan, Copper complex, Polymer nano-composite Received : 10 November 2017, Accepted : 21 April 2018 1. Introduction Electrode modifications with redox-active moieties or a functional groups has gain a great interest, due to their fundamental importance in electrochemical catalysis and bio-sensing where transition metal com- plexes are used as an electro-catalyst due to their tun- able redox potential [1-3]. Tetra dentate Schiff base ligands have been extensively used as catalysts in organic reactions and bio-mimetic enzymatic reac- tions [4,5]. Salen based electro-active complexes and their polymers have potential applications in the field of electro-catalysts, chemical sensors and optical devices [6,7]. The metal complexes are often coated on the electrode surfaces either by electro-deposition or immobilizing them with polymer matrix for the catalytic purposes[8-10]. Copper complexes of salen- type ligands are important in some biochemical pro- cesses, and DNA cleavage and antimicrobial activity [11-14]. Cu-salen complexes and metal organic frame work have been prepared and their properties had been studied well [15-17]. Chitosan is an amino-polysaccharide prepared by deacetylation of chitin, which is discarded as indus- trial waste so it can be considered as a low cost and nonhazardous polymer [18,19]. Chitosan bears free amine groups which are used for the immobilization of the metal complexes and redox mediators [20-23]. Currently, much attention has been focused on devel- oping new nano-materials, which are used for signal amplification in electrochemical methods [24]. Con- ducting nanomaterials with a larger surface area are the potential candidates for biomolecules immobili- zation and signal amplifications [25]. Among the available materials used, carbon nano-materials are the most exciting because of their unique physical, chemical and mechanical properties [26,27]. Hydrogen peroxide is a vital compound in the bio- logical transformations also widely used in several *E-mail address: shinws@sogang.ac.kr, hdj739@gmail.com DOI: https://doi.org/10.5229/JECST.2018.9.3.169 Research Article Journal of Electrochemical Science and Technology