Fabrication of a Fe₂O₃ Nanoparticles Implantation‐modified Electrode and its Applications in Electrochemical Sensing

Abstract

A novel Fe2O3 modified indium tin oxide electrode (Fe2O3/ITO) was fabricated by iron ion‐implantation method first, and then annealed at 300 °C. Fe2O3/ITO reveals good catalytic performance toward hydrogen peroxide (H2O2) in phosphate buffer solution due to the Fe(II)/Fe(III) redox couple. Amperometric response shows a linear dependency on the H2O2 concentration ranging up to 360 μM with a detection limit of 0.3 μM. Moreover, electrocatalytic activity based on rarely reported higher oxidation states of iron (tentatively assigned to Fe(IV)) was shown to allow the reliable detection of glucose and cysteine. The results show promising application potential of the proposed electrode.

Creating a Low‐Potential Redox Polymer for Efficient Electroenzymatic CO2 Reduction

“…[26] The D app value of the Cc-PAA redox polymer was determined by the Randles-Sevcik equation (Figure S4). [18,27] Thet hickness of the 10 % substituted Cc-PAA redox polymer ( Figure S5) bioelectrodes after pretreatment by cyclic voltammetry (to induce any swelling effects of the polymer film) was determined to be approximately 80 mmbyconfocal laser fluorescence scanning microscopy.T he resulting D app was determined to be 5.20 10 À8 cm 2 s À1 ,a ssuming the redox polymer matrix to be cylindrical. [28] To confirm the selectivity of formate production by the Mo-FDH/Cc-PAA bioelectrode,b ulk electrolysis was performed with an applied potential of À0.66 Vv s. SHE for 90 min, using 50 mm NaHCO 3 as the CO 2 source.W e employed as econdary enzymatic assay to quantify the amount of formate,w hereby NAD-dependent FDH (under aerobic conditions to deactivate Mo-FDH) was added after bulk electrolysis to reduce NAD + by the oxidation of formate that had been produced by Mo-FDH (NAD + and NADdependent FDH were only included after bulk electrolysis had been terminated;F igure S6).…”

The New Ion-Selective Electrodes Developed for Ferric Cations Determination, Modified with Synthesized Al and Fe−Based Nanoparticles

“…Moreover, these NPs are easy to produce and offer a wide range of biomedical applications, especially hematite and magnetite [ 1 , 6 ]. The iron oxide NPs are used as sensor modifiers for the determination of various analytes, such as hydrogen peroxide [ 17 ], glucose [ 18 ], Pb, Zn, Cd [ 19 ], Cl [ 13 ], F [ 20 ], nitrites [ 21 ] and some organic compounds [ 22 , 23 , 24 ]. The technology of iron oxide NPs synthesis has been highly developed and brought to a level where it is possible to obtain the desired phase and size of NPs by defining the synthesis process [ 25 ].…”

Iron Oxide Nanoparticle and Multiwalled Carbon Nanotube Modified Glassy Carbon Electrodes. Application to Levodopa Detection

“…Iron oxide nanoparticles (IONP) have been used independently or in combination with other materials (nanomaterials, polymers, proteins, etc.) , for the construction of (bio)sensors, presenting improved responses, excellent electrocatalytic activity, and high sensitivity in the detection of analytes in the health, environment and agriculture fields. In particular, the combination with MWCNT has been shown to bring additional electrocatalytic advantages and enhanced performance, besides offering simplicity of construction and low cost .…”