Antioxidant Sensors Based on Iron Diethylenetriaminepentaacetic Acid, Hematin, and Hemoglobin Modified TiO₂ Nanoparticle Printed Electrodes

Abstract

Antioxidant amperometric sensors based on iron-containing complexes and protein modified electrodes were developed. Indium tin oxide glass was printed with TiO(2) nanoparticles, onto which iron-containing compounds and protein were adsorbed. When applied with negative potentials, the dissolved oxygen is reduced to H(2)O(2) at the electrode surface, and the H(2)O(2) generated in situ oxidizes Fe(II) to Fe(III), and then electrochemical reduction of Fe(III) therefore gives rise to a catalytic current. In the presence of antioxidants, H(2)O(2) was scavenged, the catalytic current was reduced, and the decreased current signal was proportional to the quantity of existing antioxidants. A kinetic model was proposed to quantify the H(2)O(2) scavenging capacities of the antioxidants. With the use of the sensor developed here, antioxidant measurements can be done quite simply: put the sensor into the sample solutions (in aerobic atmosphere), perform a cathodic polarization scan, and then read the antioxidant activity values. The present work can be complementary to the previous studies of antioxidant sensor techniques based on OH radicals and superoxide ions scavenging methods, but the sensor developed here is much easier to fabricate and use.

Antioxidant Assay Based on Quenching of Photocatalytically Generated Reactive Oxygen Species

“…Recently, the OH radical quenching [8] , H 2 O 2 quenching [9] , H 2 O 2 and OH radical quenching [10] electrochemical methods were reported for the antioxidant test, and different kinetic models were developed to compare the antioxidant activity. Niu's group developed antioxidant test methods based on quenching photocatalytic generated species (e.g., positive holes and ROS) [11][12][13] .…”

Electrochemical antioxidant screening and evaluation based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE)

“…[2]. To protect living organisms and counteract the deleterious effects of ROS, complex and sophisticated endogenous and exogenous antioxidant systems are evolved in organisms [3]. The exogenous antioxidant system can be provided by chemical antioxidants such as ascorbic acid, phenolic compounds and flavonoids, which exist in fruit, vegetables and beverages.…”

Electrochemical Pseudo‐Titration of Water‐Soluble Antioxidants

“…Electrochemical-based sensors have been used for measuring the AO activity due to their simple, fast and reliable analytical performance on biological and food samples [29][30][31][32][33][34][35][36]. Moreover, electrochemical strategies can also take into account the complete range of chemical and biochemical interactions between all present species, including recycling or auto-oxidation processes.…”