ABSTRACT
Amperometric nanobiosensors are crucial time and cost effective analytical tools for the detection of a wide range of bioanalytes, viz. glucose present in complex environments at very low concentrations. Although the excellent analytical performance of nanobiosensors is undoubted, their exact molecular structure often remains unclear. Here, by combining advanced nanoanalytical approaches with theoretical modeling, we conducted a comprehensive study towards the investigation of the molecular structure of a hybrid GOx/Nafion/Pd-NPs layer deposited by electroplating from the multicomponent electrolyte solution on the surface of screen printed electrodes modified with graphene oxide. Specifically, we revealed that Pd2+ cations were adsorbed on GOx amino acid residues, forming the GOx·nPd2+ enzymatic complex. The highest adsorption energy of Pd2+ cations on GOx was found during their interaction with the side chains of basic amino acids and methionine. In addition, we showed and fully validated the end-structure of the one-step designed GOx/Nafion/Pd-NPs nanobiosensor as a structural model mainly composed of GOx and water molecules incorporated into the metal-polymer scaffold. Our approach will thus serve as a guideline for the study of molecular interactions occurring in complex systems and will contribute to the design of the next generation of hybrid nanobiosensors. The proposed mechanism, driving the self-assembly of the hybrid layer, will allow us to construct modular enzymatic nanoanalytical devices with tailored sequences in the future.
Subject(s)
Biosensing Techniques , Glucose Oxidase , Enzymes, Immobilized , Fluorocarbon Polymers , GlucoseABSTRACT
Insulinoresistance (IR) and endothelial dysfunction (ED) take part in forming cardiovascular complications. Hyperglycemia, dyslipidemia, and compensatory hyperinsulinemia are triggering factors in the development of ED in diabetes mellitus. Hyperactivation of the renin--angiotensin--aldosterone system and increasing influence of the sympathoadrenal system play an important role in the appearance of ED, which is characterized by a decrease in the synthesis of nitric oxide and an increase in the production of vasoconstrictors. At present, drugs used for ED correction only indirectly influence the functioning of endothelial cells. Eight pharmacological groups including more than 30 drugs are reviewed, which are capable of improving the endothelial function. Progress in the pharmacotherapy of ED stimulates the development of approaches to the individual choice of drugs and the directed correction of the functional state of vascular endothelium.
