Optical and electrochemical behavior of new nano-sized complexes based on gold-colloid and Co-porphyrin derivative in the presence of H2O2

• Published in: Journal of alloys and compounds Vol. 686; pp. 896 - 904
• Main Authors: Fagadar-Cosma, Eugenia, Sebarchievici, Iuliana, Lascu, Anca, Creanga, Ionela, Palade, Anca, Birdeanu, Mihaela, Taranu, Bogdan, Fagadar-Cosma, Gheorghe
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.11.2016
• Subjects: Co-porphyrin; Electrocatalysis; Gold colloid; Modified GC-electrodes; UV–vis spectroscopy; Voltammetry; UV–vis spectroscopy; Electrocatalysis; Modified GC-electrodes; Voltammetry; Co-porphyrin; Gold colloid
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.06.246

A wide band absorption hybrid material, prepared from a metalloporphyrin and gold nanoparticles (nAu) with the purpose to develop optical and electrochemical detection of hydrogen peroxide was investigated. Gold nanoparticles smaller than 20 nm were obtained and functionalized with Co(II) 5,10,15,20-meso-tetra(3-hydroxyphenyl)porphyrin (Co-3OHPP). The dependence between the intensity of absorption of the gold plasmonic band and the increasing concentration of Co-3OHPP proved that nAu is sensitive to porphyrin detection, showing potential in early medical diagnosis. The nAu-porphyrin complex was exposed to increased amounts of H2O2 to prove its sensing capacity and the changes of the absorption spectra were monitored by UV–vis spectroscopy. The AFM and FT-IR studies showed significant structural and morphological modifications of the hybrid material after H2O2 exposure. In order to verify if the range of physiologically-relevant H2O2 concentration levels (5–35 μM) might be detected, three modified glassy carbon (GC) electrodes were realized, by deposition onto their surfaces of nAu and Co-porphyrin (alone and in successive layers) and were tested to evidence the electrochemical response for H2O2. The comparative linear and cyclic voltammetry of the bare and modified GC electrodes evidenced an increased electrocatalytic effect on the reduction of H2O2 onto GC electrode modified with nAu/Co-3OHPP ordered layers. [Display omitted] •Wide UV–vis absorption band gold-metalloporphyrin hybrid was obtained.•Gold nanoparticles are sensitive to trace amounts of Co-porphyrin.•Gold-Co-porphyrin complex is sensitive to H2O2 detection by UV–vis spectroscopy.•Co-porphyrin/gold nanoparticle-modified glassy carbon electrodes were tested.•Modified electrodes show electrocatalytic effect on the reduction of H2O2.