Electrocatalysts Based on Novel Carbon Forms for the Oxidation of Sulphite

Described herewith is an electrochemical method to decontaminate sulphur compounds. Studies were carried out of sulphites (SO32−) oxidation on a range of anode catalysts. The electrocatalysts were characterized by scanning electron microscopy, XRD, XPS and BET. Polarization curves were recorded of electrodes incorporating lyophilized higher fullerenes and manganese oxides. The experiments showed that lyophilized higher fullerenes and C60/C70 fullerene catalysts in conjunction with manganese oxides electrochemically convert sulphites (SO32−) to sulphates (SO42−). The oxidation products do not poison the electrodes. The XPS analysis shows that the catalysts incorporating DWCNTs, MWCNTs and higher fullerenes have a higher concentration of sp3C carbon bonding leading to higher catalytic activity. It is ascertained that higher fullerenes play a major role in the synthesis of more effective catalysts. The electrodes built by incorporating lyophilized catalysts containing higher fullerenes and manganese oxides are shown as most promising in the effective electrochemical decontamination of industrial and natural wastewaters.

Electrochemical Detection of Waterborne Bacteria Using Bi-Functional Magnetic Nanoparticle Conjugates

Detection of microbial contamination in water is imperative to ensure water quality. We have developed an electrochemical method for the detection of E. coli using bi-functional magnetic nanoparticle (MNP) conjugates. The bi-functional MNP conjugates were prepared by terminal-specific conjugation of anti-E. coli IgG antibody and the electroactive marker ferrocene. The bi-functional MNP conjugate possesses both E. coli-specific binding and electroactive properties, which were studied in detail. The conjugation efficiency of ferrocene and IgG antibodies with amine-functionalized MNPs was investigated. Square-wave voltammetry enabled the detection of E. coli concentrations ranging from 101–107 cells/mL in a dose-dependent manner, as ferrocene-specific current signals were inversely dependent on E. coli concentrations, completely suppressed at concentrations higher than 107 cells/mL. The developed electrochemical method is highly sensitive (10 cells/mL) and, coupled to magnetic separation, provides specific signals within 1h. Overall, the bi-functional conjugates serve as ideal candidates for electrochemical detection of waterborne bacteria. This approach can be applied for the detection of other bacteria and viruses.

Sub-second striatal dopamine dynamics assessed by simultaneous fast-scan cyclic voltammetry and fluorescence biosensor

Fast-scan cyclic voltammetry (FSCV) is an electrochemical method used to detect dopamine on a subsecond time scale. Recordings using FSCV in freely behaving animals revolutionized the study of behaviors associated with motivation and learning. Despite this advance, FSCV cannot distinguish between catecholamines, which limits its use to brain regions where dopamine is the predominant neurotransmitter. It has also been difficult to detect dopamine in vivo in some striatal subregions with FSCV. Recently, fluorescent biosensors for dopamine were developed, allowing for discrimination between catecholamines. However, the performance of these biosensors relative to FSCV has not been determined. Thus, we compared fluorescent photometry responses of the dopamine biosensor, dLight, with FSCV. We also used dLight photometry to assess changes in tonic and phasic dopamine, which has not been possible with FSCV. Finally, we examined dopamine dynamics during Pavlovian conditioning in striatal subregions, including the dorsolateral striatum where dopamine measurements are challenging with FSCV.

Metal- and oxidant-free electrochemically promoted oxidative coupling of amines

This paper presents a metal-free and external oxidant-free electrochemical method for the oxidative coupling methodology of amines in moderate to satisfactory yields.

Non-Kolbe electrolysis of N-protected-α-amino acids: a standardized method for the synthesis of N-protected (1-methoxyalkyl)amines

A high-yielding, standardized, electrochemical method for the synthesis of N-protected (1-methoxyalkyl)amines using commercially available, user-friendly kit – not only for “electro-curious” chemists.

Cure Kinetics of Samarium-doped Fe3O4/Epoxy Nanocomposites

There was a question on “how lanthanides doping in iron oxide affects cure kinetics of epoxy-based nanocomposites?” To answer, we synthesized samarium (Sm)-doped Fe3O4 nanoparticles via electrochemical method and characterized it using FTIR, XRD, FE-SEM, EDX, TEM, and XPS analyses. The magnetic particles were uniformly dispersed in epoxy resin to increase the curability of the epoxy/amine system. The effect of the lanthanide dopant on the curing reaction of epoxy with amine was explored by modeling DSC experimental data based on model-free methodology. It was found that Sm3+ in the structure of Fe3O4 crystal participates in cross-linking of epoxy by catalyzing the reaction between epoxide rings and amine groups of curing agents. In addition, the etherification reaction of active OH groups on the surface of nanoparticles reacts with epoxy rings which prolongs the reaction time at the late stage of reaction where diffusion is the dominant mechanism.