1 3 J IRAN CHEM SOC DOI 10.1007/s13738-017-1106-0 ORIGINAL PAPER High-performance electrochemical sensor based on electrodeposited iron oxide nanoparticle: catecholamine as analytical probe Mohammad Mazloum-Ardakani 1 · Mehdi Maleki 1 · Alireza Khoshroo 1 Received: 29 December 2015 / Accepted: 13 March 2017 © Iranian Chemical Society 2017 scientific interest of the materials, but also for their broad range of applications [1]. Nanoparticles have the signifi- cantly advance nanomaterial-based applications which can be made to promote the electron transfer reactions and pro- vide great catalytic surface areas for the modification of electrode surfaces and enhanced electrochemical reactivity [2–4]. In recent years, finding materials containing advan- tages such as easy preparation, low cost, high stability, and easily separation from solution by an external magnetic field have been the center of attention of researchers [5]. Among various materials, iron oxide nanoparticles have received a lot of attention due to high abundance, low cost, high resistance to corrosion, large surface area-to-volume ratio, and environmentally friendly properties have been more attention [6, 7]. Iron oxide, Fe 2 O 3 (hematite), is the thermodynamic stable crystallographic phase of iron oxide under ambient conditions, which widely used as catalyst, pigment, gas sensor, and electrode materials [8, 9]. Fe 2 O 3 is an attractive material to consider for photo-electrochem- ical research into solar energy conversion. It shows good stability under operation in aqueous solutions as it resists both dark and photo-corrosion, and its relatively small band gap energy of 2.2 eV enables it to absorb most of the photons of solar spectrum [7]. Many groups have synthe- sized Fe 2 O 3 nanoparticle through various methods. Goyal et al. [10] used ultrasonic mist chemical vapor deposition method for synthesized Fe 2 O 3 nanopowder. The Fe 2 O 3 nanopowder was used to modify electrode for determina- tion of dopamine. Doping of different metal ions or metal oxides into Fe 2 O 3 will find new application or improve the performance of existing applications. For example, Suresh et al. [11] reported that the Co-doped a-Fe 2 O 3 powders which synthesized by the hydrolysis method exhibit higher sensitivity and better selectivity to ascorbic acid and uric acid than the pure Fe 2 O 3 . It is still a challenge to synthesize Abstract In this paper, we report the synthesis and elec- trocatalytic activity of electrodeposited Fe 2 O 3 nanoparti- cles modified on a glassy carbon electrode as highly sen- sitive sensors for determination of catecholamines. Results showed that the Fe 2 O 3 nanoparticles on a glassy carbon electrode exhibit excellent catalytic activity toward cat- echolamines oxidation, including levodopa, dopamine, and epinephrine, resulting in a marked lowering in the peak potential and considerable improvement of the peak cur- rent as compared to the electrochemical activity at the bare glassy carbon electrode. The electrochemical characteriza- tions of catecholamines were performed using cyclic vol- tammetry, chronoamperometry, and differential pulse vol- tammetry techniques. The electrocatalytic currents increase linearly with the levodopa, dopamine, and epinephrine con- centrations in the ranges of 0.0625–1000, 0.25–1500, and 0.125–1000 μM, respectively, and the detection limits (3σ) were 24 ± 2, 14 ± 2, and 12 ± 2 nM, respectively. Keywords Magnetic nanoparticles · Levodopa · Dopamine · Epinephrine · Electrocatalysis · Modified electrodes · Hematite Introduction Today the use of nanomaterials has been increased due to their unique properties, including their remarkable elec- trical, chemical, mechanical not only for the fundamental * Mohammad Mazloum-Ardakani mazloum@yazduni.ac.ir 1 Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Islamic Republic of Iran