Contents lists available at ScienceDirect Reactive and Functional Polymers journal homepage: www.elsevier.com/locate/react An innovative method to electrochemical branching of chitosan in the presence of copper nanocubics on the surface of glassy carbon and its electrical behaviour study: A new platform for pharmaceutical analysis using electrochemical sensors Mahsa Feyziazar a , Mohammad Hasanzadeh a,b, ⁎ , Fatemeh Farshchi b , Arezoo Saadati a , Soodabeh Hassanpour c a Pharmaceutical Analysis Research Center, Tabriz University of Medical Sciences, Tabriz, Iran b Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran c Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran ARTICLE INFO Keywords: Chitosan Polymer electro-chemical modifcation Drug Nano-composite Biocompatible polysaccharide ABSTRACT Chitosan (CS) as biocompatible and non-toxic polymer is derived from de-acetylation of chitin and consists of N- acetylglucosamine and glucosamine unites. The ability of CS to form solid deposits similar to hydrogels and the possibility of electrodeposition on the surface of the electrode as a thin flm, makes it valuable for the pre- paration of micro-sensors and nano-biosensors. In this work, a novel method for the electrochemical branching of CS on the surface of glassy carbon was introduced. New modifed copper electrodes were fabricated as electrochemical sensors for the determination of mefenamic acid and Indomethacin. Two types of modifed copper electrodes; the frst based on Cu nanocubes (NC) to identify mefenamic acid, and the other one based on chitosan modifed by Cu NCs to detection of indomethacin. Electrochemical behavior and morphology of the copper nanocubes modifed copper electrode CuNCs/CuE and chitosan modifed copper nanocubics coated on copper electrode (CS-Cu NCs/CuE) were studied using diferential pulse voltammetry (DPV) and cyclic vol- tammetry (CV). The results confrmed the presence of CS-Cu NCs/Cu NCs on the electrode surface. Also, using CV technique it has found that Cu NCs and PCS- Cu NCs led to increased oxidation peak current, by adsorption of indomethacin. However, the anodic peak current was increased by CuNCs for the mefenamic acid. There is a linear relationship between the anodic peak current and mefenamic acid/indomethacin concentration in the range of 1 nM to 10 mM, where the low limit of quantifcation (LLOQ) was 1 nM for the those drugs. Therefore, the prepared electrodes have many benefts such as high sensitivity, selectivity, and stability for the determi- nation of mefenamic acid and indomethacin in human serums and pharmaceutical preparation. 1. Introduction Chitosan as biocompatible and non-toxic polymer is derived from deacetylation of chitin and consists of N-acetylglucosamine and glu- cosamine unites [1,2]. This polysaccharide is dissolved in weak acidic solutions as cationic electrolytes, and are chemically modifed through covalent bonding of their amine (NH 2 ) and hydroxyl groups with other molecules [3,4]. Due to its functional and structural characteristics, CS is used in many felds including drug delivery [5], environment, bio- technology [6], agriculture [7], and biomedicine [8]. CS is also used to develop sensor technology [9–11]. Sensors measure the concentration of target analysis in the form of an electrical or optical signals. CS, as a natural polymer, is used to modify the converter surface. The ad- vantages of CS include anti-bacterial attributes, biodegradability, having functional groups, high ability to form the low-cost, non-toxi- city, and biocompatible flm on the surface of diferent substrates [12]. In addition, the ability of CS to form solid deposits similar to hydrogels and the possibility of electrodeposition on the surface of the electrode as a thin flm, makes it valuable for the preparation of microsensors and nanobiosensors [13]. In recent years, various types of biosensors with the support of CS have been reported to detect conductive ions [14], glucose [15], urea [1], and hydrogen peroxide [16]. Non-steroidal anti-infammatory drugs (NSAIDs) are among the most important drugs widely used in medicine. These drugs inhibit https://doi.org/10.1016/j.reactfunctpolym.2019.104402 Received 24 July 2019; Received in revised form 10 October 2019; Accepted 29 October 2019 ⁎ Corresponding author at: Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 51664, Iran. E-mail address: hasanzadehm@tbzmed.ac.ir (M. Hasanzadeh). Reactive and Functional Polymers xxx (xxxx) xxxx 1381-5148/ © 2019 Published by Elsevier B.V. Please cite this article as: Mahsa Feyziazar, et al., Reactive and Functional Polymers, https://doi.org/10.1016/j.reactfunctpolym.2019.104402