Case study into the successful emergency production and certification of a filtering facepiece respirator for Belgian hospitals during the COVID-19 pandemic.

The SARS-CoV-2 pandemic presented European hospitals with chronic shortages of personal protective equipment (PPE) such as surgical masks and respirator masks. Demand outstripped the production capacity of certified European manufacturers of these devices. Hospitals perceived emergency local manufacturing of PPE as an approach to reduce dependence on foreign supply. The fact of a pandemic does not circumvent the hospital's responsibility to provide appropriate protective equipment to their staff, so the emergency production needed to result in devices that were certified by testing agencies. This paper is a case study of the emergency manufacturing of respirator masks during the first month of the first wave of SARS-CoV-2 pandemic and is separated into two distinct phases. Phase A describes the three-panel folding facepiece respirator design, material sourcing, performance testing, and an analysis of the folding facepiece respirator assembly process. Phase B describes the redevelopment of individual steps in the assembly process.

Electrochemical analysis of speedball-like polydrug samples.

Increasing global production, trafficking and consumption of drugs of abuse is an emerging threat to people's health and safety. Electrochemical approaches have been proved to be useful for on-site analysis of drugs of abuse. However, less attention has been focused on the analysis of polydrug samples, even though these samples pose severe health concerns, especially when stimulants and depressants are combined, as is the case of speedball, a mixture of cocaine and heroin. In this work, we provide solutions for the selective detection of cocaine (stimulant) in polydrug samples adulterated with heroin and codeine (depressants). The presence of either one of these compounds in cocaine street samples leads to an overlap with the cocaine signal in square-wave voltammetry measurements at unmodified carbon screen-printed electrodes, leading to inconclusive screening results in the field. The provided solutions to this problem consist of two parallel approaches: (i) cathodic pretreatment of the carbon screen-printed electrode surface prior to measurement under both alkaline and neutral conditions and (ii) electropolymerization of orthophenylenediamine on graphene modified carbon screen-printed electrodes prior to measurement under neutral conditions. Both strategies allow simultaneous detection of cocaine and heroin in speedball samples as well as simultaneous detection of cocaine and codeine. Implementing these strategies in portable devices holds great potential for significantly improved accuracy of on-site cocaine screening in polydrug samples.

Unraveling the Mechanisms Behind the Complete Suppression of Cocaine Electrochemical Signals by Chlorpromazine, Promethazine, Procaine, and Dextromethorphan.

The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector.

Disposable electrodes from waste materials and renewable sources for (bio)electroanalytical applications.

The numerous advantages of disposable and screen-printed electrodes (SPEs) particularly in terms of portability, sensibility, sensitivity and low-cost led to the massive application of these electroanalytical devices. To limit the electronic waste and recover precious materials, new recycling processes were developed together with alternative SPEs fabrication procedures based on renewable, biocompatible sources or waste materials, such as paper, agricultural byproducts or spent batteries. The increased interest in the use of eco-friendly materials for electronics has given rise to a new generation of highly performing green modifiers. From paper based electrodes to disposable electrodes obtained from CD/DVD, in the last decades considerable efforts were devoted to reuse and recycle in the field of electrochemistry. Here an overview of recycled and recyclable disposable electrodes, sustainable electrode modifiers and alternative fabrication processes is proposed aiming to provide meaningful examples to redesign the world of disposable electrodes.