Base‐Assisted Electrografting of Aromatic Amines

Zwitterionic oligomers of 3-aminobenzoic acid on screen-printed electrodes: structure, properties and forensic application

The popularity and rapid spread of new psychoactive substances is why there is an urgent need for their fast monitoring in saliva in the field with electrodes modified with a selective receptor. Oligomers of electrochemically oxidized 3-aminobenzoic acid that are deposited on the surface of a graphite screen-printed electrode (o-3ABA/G/SPE) is proposed as a selector for the analyte of forensic interest. The oligomeric structure and existence of the zwitterionic form of o-3ABA on the G/SPE surface was confirmed using scanning electron microscopy, Raman spectroscopy and cyclic voltammetry techniques. The equilibrium adsorption constants between o-3ABA and 2-aminoindane (primary amine: Kads(2-AI) = 5.31 × 104) and selected synthetic cathinones (secondary amine: Kads(butylone) = 6.12 × 105, tertiary amines: Kads(MDPV) = 3.41 × 104 and Kads(naphyrone) = 1.01 × 104) were estimated using the electrochemical impedance spectroscopy (EIS) technique. The EIS technique was applied for determining a 1.0 μM concentration of 2-AI (RSD 3.5-4.0%) and butylone (RSD 4.9-6.4%) in the model and oral fluid samples.

Homogeneous and heterogeneous molecular catalysts for electrochemical reduction of carbon dioxide

Carbon dioxide (CO2) is a greenhouse gas whose presence in the atmosphere significantly contributes to climate change. Developing sustainable, cost-effective pathways to convert CO2 into higher value chemicals is essential to curb its atmospheric presence. Electrochemical CO2 reduction to value-added chemicals using molecular catalysis currently attracts a lot of attention, since it provides an efficient and promising way to increase CO2 utilization. Introducing amino groups as substituents to molecular catalysts is a promising approach towards improving capture and reduction of CO2. This review explores recently developed state-of-the-art molecular catalysts with a focus on heterogeneous and homogeneous amine molecular catalysts for electroreduction of CO2. The relationship between the structural properties of the molecular catalysts and CO2 electroreduction will be highlighted in this review. We will also discuss recent advances in the heterogeneous field by examining different immobilization techniques and their relation with molecular structure and conductive effects.

Nanofabrication Techniques in Large-Area Molecular Electronic Devices

The societal impact of the electronics industry is enormous—not to mention how this industry impinges on the global economy. The foreseen limits of the current technology—technical, economic, and sustainability issues—open the door to the search for successor technologies. In this context, molecular electronics has emerged as a promising candidate that, at least in the short-term, will not likely replace our silicon-based electronics, but improve its performance through a nascent hybrid technology. Such technology will take advantage of both the small dimensions of the molecules and new functionalities resulting from the quantum effects that govern the properties at the molecular scale. An optimization of interface engineering and integration of molecules to form densely integrated individually addressable arrays of molecules are two crucial aspects in the molecular electronics field. These challenges should be met to establish the bridge between organic functional materials and hard electronics required for the incorporation of such hybrid technology in the market. In this review, the most advanced methods for fabricating large-area molecular electronic devices are presented, highlighting their advantages and limitations. Special emphasis is focused on bottom-up methodologies for the fabrication of well-ordered and tightly-packed monolayers onto the bottom electrode, followed by a description of the top-contact deposition methods so far used.

Antifouling Activities of Immobilized Ferrocenyl Glucose on a Glassy Carbon Surface

Polar coatings are used to protect surfaces from marine fouling based on the formation of a hydrated surface layer, which acts as a barrier to marine microorganisms. In this context, we have developed a material with glucose bound to ferrocene to prevent surface absorption. Glucose brings the polarity while ferrocene has the role of varying the state of charge of the surface. We therefore describe the synthesis of 6-deoxy-6-(4-ferrocenyl-1H-1,2,3-triazol-1-yl)-1-(4-aminophenyl)-β-D-glucopyranose 6 and its immobilization on the surface of a C electrode and develop a methodology used for antibacterial testing. We were able to demonstrate that the immobilization of glucose 6 could be done in an artificial seawater environment by oxidation of an amine. The use of a 96-microwell platform equipped with electrodes for cyclic voltammetry, linked to a potentiostat, allowed the electrical solicitation of the coating in the presence of marine bacteria with a greater number of biological replicates. We have shown that the coating has an antibacterial effect, and this effect is accentuated when the coating is electrically stressed, resulting in the appearance and disappearance of charge on ferrocene, a phenomenon that seems to be conducive to colonization by bacteria.