Nanomolar Detection of Dopamine at ZnO/Graphene Modified Carbon Paste Electrode

Common Transition Metal Oxide Nanomaterials in Electrochemical Sensors for the Diagnosis of Monoamine Neurotransmitter‐Related Disorders

Monoamine neurotransmitters are essential for learning, mental alertness, emotions, and blood flow, among other functions. Fatal neurological disorders that signal the imbalance of these biomolecules in the human system include Parkinson's disease, myocardial infarction, Alzheimer's disease, hypoglycemia, Schizophrenia, and a host of other ailments. The diagnosis of these monoamine neurotransmitter‐related conditions revolves around the development of analytical tools with high sensitivity for the four major monoamine neurotransmitters namely dopamine, epinephrine, norepinephrine, and serotonin. The application of electrochemical sensors made from notable metal oxide nanoparticles or composites containing the metal oxide nanoparticles for the detection of these monoamine neurotransmitters was discussed herein. More importantly, the feasibility of the application of the ZnO, CuO, and TiO2 nanoparticle‐based electrochemical sensors for a comprehensive diagnosis of monoamine neurotransmitter‐related conditions was critically investigated in this review.

Electrochemical sensing of hydrogen peroxide on a carbon paste electrode modified by a silver complex based on the 1,3-bis(1H-benzimidazole-2-yl)propane ligand

A new carbon paste electrode (Ag-CPE) modified with a nitrogen heterocyclic silver(I) complex, [Ag2(BBP)2](pic)2·CH3OH (BBP = 1,3-bis(1H-benzimidazol-2-yl)propane, pic = picrate), was developed as a highly sensitive and simple electrochemical sensor for the determination of hydrogen peroxide. The Ag(I) complex was prepared by an interface reaction and characterized by elemental analysis, IR and UV/Vis spectra and single crystal X-ray diffraction. The Ag(I) complex shows a dinuclear cluster structure, which is formed by two BBP ligands bridging two Ag (I) centers and an Ag–Ag interaction (d Ag–Ag = 3.0875 Å). Cyclic voltammetry and chronoamperometry studies showed that the electrochemical sensing performance of Ag-CPE for H2O2 was improved in 0.2 m phosphate buffer solution (PBS, pH = 6). The electrochemical H2O2 sensor Ag-CPE exhibits a wide linear detection range from 0.5 to 4.0 mm and a lower detection limit of 0.39 μm with a relatively high sensitivity of 6.77 μA mm −1. Moreover, the sensor also shows good anti-interference properties and stability. The results prove that the Ag(I) complex based on the bis(benzimidazole) ligand may be an efficient component of electrode materials.