Electrodeposition of dopamine onto carbon fiber microelectrodes to enhance the detection of Cu2+ via fast-scan cyclic voltammetry.

The etiology of neurodegenerative diseases is poorly understood; however, studies have shown that heavy metals, such as copper, play a critical role in neurotoxicity, thus, adversely affecting the development of these diseases. Because of the limitations associated with classical metal detection tools to obtain accurate speciation information of ultra-low concentrations of heavy metals in the brain, analysis is primarily performed in blood, urine, or postmortem tissues, limiting the translatability of acquired knowledge to living systems. Inadequate and less accurate data obtained with such techniques provide little or no information for developing efficient therapeutics that aid in slowing down the deterioration of brain cells. In this study, we developed a biocompatible, ultra-fast, low-cost, and robust surface-modified electrode with carbon fibers by electrodepositing dopamine via fast-scan cyclic voltammetry (FSCV) to detect Cu2+ in modified tris buffer. We studied the surface morphology of our newly introduced sensors using high-resolution images by atomic force microscopy under different deposition conditions. The limit of detection (LOD) of our surface-modified sensor was 0.01 µM (0.64 ppb), and the sensitivity was 11.28 nA/µM. The LOD and sensitivity are fifty and two times greater, respectively, compared to those of a bare electrode. The sensor's response is not affected by the presence of dopamine in the matrix. It also exhibited excellent stability to multiple subsequent injections and repeated measurements of Cu2+ over a month, thus showing its strength to be developed into an accurate, fast, robust electrochemical tool to monitor ultra-low concentrations of heavy metals in the brain in real time.

Recent Advances in Electrochemical Tools for Virus Detection.

Virus detection at the point-of-care facility has become an alarming topic in the research community. The latest coronavirus pandemic has highlighted the limitations of current conventional virus detection methods. Compared to nonelectrochemical sensors, electrochemical sensors provide the ideal platform for rapid, cheap, fast, sensitive, and selective diagnosis of several viruses, particularly at point-of-care facilities. This article highlights the most promising studies reported over the past decade to detect a broad spectrum of viruses using voltammetry, amperometry, and electrochemical impedance spectroscopy.

Multifunctional Loblolly Pine-Derived Superactivated Hydrochar: Effect of Hydrothermal Carbonization on Hydrogen and Electron Storage with Carbon Dioxide and Dye Removal.

Pore modulation via hydrothermal carbonization (HTC) needs investigation due to its crucial effect on surface that influences its multirole utilization of such ultraporous sorbents in applications of energy storage- hydrogen and capacitive- as well as for pollutant abatement- carbon capture and dye removal. Hence, loblolly pine was hydrothermally carbonized followed by KOH activation to synthesize superactivated hydrochars (SAH). The resulting SAHs had specific surface area (SSA) 1462-1703 m2/g, total pore (TPV) and micropore volume (MPV) of 0.62-0.78 cm3/g and 0.33-0.49 cm3/g, respectively. The SAHs exhibit excellent multifunctional performance with remarkably high atmospheric CO2 capture of 145.2 mg/g and high pressure cryogenic H2 storage of 54.9 mg/g. The fabricated supercapacitor displayed substantial specific capacitance value of maximum 47.2 Fg-1 at 1 A g-1 in 6 M KOH and highest MB dye removal of 719.4 mg/g. Higher HTC temperature resulted in increased surface porosity as higher SSA, TPV benefitted H2 storage and MB dye removal while superior MPV favored CO2 capture. Moderate HTC temperature ensured higher mesopore-to-macropore volume ratio favoring electrochemical performance. Isotherm modelling of the adsorbates was compared using models: Langmuir, Freundlich, Langmuir- Freundlich and Temkin.

Electrochemical detection of Cd(ii) ions in complex matrices with nanopipets.

Heavy metal contamination and its detrimental health effects are a growing concern globally. Several metal mitigation systems and regulatory approaches have been implemented to minimize the negative impacts on human health. However, none of these function at maximum efficiency, mainly due to the lack of accurate information about metal speciation. Therefore, there is a critical need to develop novel, cheap, efficient, and robust metal detecting sensors. In this study, we describe the application of a nanopipet based electrochemical sensor to detect aqueous Cd(ii) ions. The inner radius of our nanopipets is ∼300 nm, and the fundamental mechanism behind our sensor's response is ion transfer between two immiscible electrolyte solutions (ITIES). The absence of redox behavior makes ITIES an excellent, attractive electrochemical tool to study various ions in aqueous solutions. In this study, we used 1,10-phenanthroline as our ionophore in the organic phase (dichloroethane) to facilitate the transfer of Cd(ii) ions from the polar aqueous phase to the less polar organic phase. Unlike previous studies, we characterized our nanopipet in complicated matrices, including, but not limited to, tris buffer and artificial seawater. We performed quantitative assessments to determine our sensor's limit of detection, stability, sensitivity, and selectivity. We further show that our nanosensor can detect free Cd(ii) ions in the presence of strong complexing agents such as ethylenediaminetetraacetic acid, 2,3-dimercaptosuccinic acid, etc. We quantified the concentration of free Cd(ii) ions in a water sample collected from a local lagoon. Thus, we showcased the power of our nanopipets to act as a robust, accurate, and efficient speciation sensor to detect Cd(ii) ions in environmental samples.