Direct Electrochemistry and Electrocatalytic Properties of Hemoglobin Immobilized on Carbon Nanotubes Ionic Liquid Electrode

Electroconductive bioplatform based on dextrin for the immobilization of hemoglobin: Application for electrochemical monitoring of H2O2

A novel biodegradable dextrin-based nanocomposite, involving polypyrrole (PPy) and hydrophilic dextrin (Dex) (PPy@Dex) was prepared using in-situ radical chemical polymerization technique. The obtained PPy@Dex bionanocomposite was fully characterized by FT-IR, XRD, FESEM, and DSC methods. The exceptional properties such as biocompatibility, high surface area, the proper functional group on the surface, and outstanding electrical conductivity of synthesized bionanocomposite made it a superior candidate over biomolecules immobilization. Electrochemical observations revealed that the PPy@Dex-coated glassy carbon electrode (GCE) demonstrated improved performance, making it a suitable substrate for immobilizing hemoglobin (Hb) and constructing an efficient biosensor. The resulting biosensor, named Hb-PPy@Dex/GCE, exhibited high activity in the reduction of hydrogen peroxide (H2O2). Amperometric examinations demonstrated an extensive linear range from 2 to 350 μM for Hb-PPy@Dex/GCE. The detection limit of the proposed approach was calculated to be 0.54 μM, following the S/N = 3 protocol.

Ag nanoparticles/PbTiO3 with in-situ photocatalytic process and its application in an ultra-sensitive molecularly imprinted hemoglobin detection

An electrochemical sensor based on loading molecularly imprinted polymers (MIP) on the material surface can improve the specificity towards the object. In this work, a T-shaped PbTiO₃ with a high active-exposed (110) facet was prepared by a hydrothermal process. Then, Ag nanoparticles (Ag NPs) modified T-shaped PbTiO₃ was obtained by in-situ photocatalytic reduced method under UV irradiation, where a hetero-junction was formed with a well lattice matching between the (111) facet of Ag⁰ and the (110) facet of PbTiO₃. A MIPs modified by Ag nanoparticles (NPs)/PbTiO₃ (MAP) electrodes was prepared via electro polymerization process by o-Phenylenediamine (o-PD) in the presence of the template molecule, bovine hemoglobin (BHb), i.e., the detected molecule. The response peak current and concentration of BHb is demonstrated with a good linear relationship in the range of 0.00294-0.41 nM (R² =0.98), and the detection limit at 0.23 pM (S/N = 3). A heterojunction between Ag NPs and high- active facet of PbTiO₃ is beneficial to oxidizing electroactive material ([Fe (CN)₆]^3-/4-), generating more BHb-imprinting cavities on the modified electrode and improving the sensitivity of sensor. The electrochemical sensor is with a simple, stable structure and high sensitivity to BHb detection. Furthermore, the sensor was successfully applied to detect BHb in the bovine serum samples.

Highly sensitive determination of perphenazine on a carbon nanocomposite ionic liquid electrode

A multi-walled carbon nanotube–ionic liquid nanocomposite was fabricated for the electrochemical detection of perphenazine, suitable for the analysis of pharmaceuticals and blood serum samples.