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Pseudomonas aeruginosa is a multidrug-resistant Gram-negative bacterium that poses a significant threat to public health, necessitating rapid and on-site detection methods for rapid recognition. The goal of the project is therefore to indirectly detect the presence of P. aeruginosa in environmental water samples targeting one of its quorum-sensing molecules, namely, (S)-N-butyryl homoserine lactone (BHL). To this aim, molecularly imprinted polymers (MIPs) were synthesized via bulk free-radical polymerization using BHL as a template molecule. The obtained MIP particles were immobilized onto screen-printed electrodes (MIP-SPEs), and the BHL rebinding was analyzed via electrochemical impedance spectroscopy (EIS). To study the specificity of the synthesized MIPs, isotherm curves were built after on-point rebinding analysis performed via LC–MS measurements for both MIPs and NIPs (nonimprinted polymers, used as a negative control), obtaining an imprinting factor (IF) of 2.8 (at Cf = 0.4 mM). The MIP-SPEs were integrated into an electrochemical biosensor with a linear range of 1 × 101–1 × 103 nM and a limit of detection (LoD) of 31.78 ± 4.08 nM. Selectivity measurements were also performed after choosing specific interferent molecules, such as structural analogs and potential interferents, followed by on-point analysis performed in spiked tap water to prove the sensor’s potential to detect the presence of the quorum-sensing molecule in environmentally related real-life samples.

Screen-printed electrochemical sensing platforms are ubiquitous within the field of electrochemistry where they provide benefits of being disposable, cost-effective, reproducible, easily customisable, portable and allow one to transfer the laboratory approach into the field. In this review, we introduce the concept of screen-printed electrodes, we summarise positive and negative aspects before moving into the current highlights of using traditional screen-printed carbon electrodes within the field of electroanalysis. We then look to cover metallic and bulk modified varieties, geometric changes (micro, microband and associated arrays), electrode activation and finally the physical length of screen-printed electrodes, providing insights for future research.

In this work we report the dramatic effects that changing the infill pattern has on the electrochemical performance of an additively manufactured electrode made from commercial filament. Electrodes were produced using six different slicing patterns and imaged to confirm how the infill pattern altered the working electrode surface. These electrodes were then electrochemically characterised against the near-ideal outer sphere redox probe [Ru(NH3)6]3+, the common inner sphere probe [Fe(CN)6]3−, and then used for the electroanalytical determination of acetaminophen. It was found that changing the infill pattern had a dramatic effect on the electrochemical performance of the electrodes. Over the course of the manuscript, it can be seen that Aligned Rectilinear and Rectilinear infill patterns perform consistently well and offer good reproducibility. On the other hand, Concentric infill pattern had noticeably poor inter-electrode reproducibility and the Hilbert Curve infill was one of the worst performing electrodes in many categories. For future work in this field, we recommend the infill pattern is always reported within the experimental section to allow other researchers to repeat work properly. Additionally, when optimising an electroanalytical sensing platform, we encourage researchers to optimise the infill pattern as it has direct influence on the analytical parameters.

In this overview, we explore the electroanalytical determination of the poisoner's poison: thallium. Thallium was named after the Greek word "thallos," meaning "green shoot" or "twig," due to its bright green spectral emission lines. It is toxic, tasteless, odourless and dissolves into water, and has been used by murderers as a challenging poison to detect and there is the need for the analytical determination of thallium. Laboratory based analytical instrumentation provide a routine methodology to measure thallium, but there is scope to develop in-the-field analytical measurements that are comparable to laboratory equipment and in some cases, they can provide even more sensitive analytical approaches. Electrochemistry can support such endeavours, where instrumentation are readily portable where electroanalytical sensors provide highly selective and sensitive outputs but yet are economical to support on-site analysis. In this review, we provide an electroanalytical overview of the current research directed toward the measurement of thallium and offer insights to future research.

Ciprofloxacin is a third-generation synthetic fluoroquinolone antibacterial drug which has been used as a broad-spectrum antibiotic to treat a number of bacterial infections. An excessive use or an overdose of ciprofloxacin can result in several adverse effects to humans and therefore its measurement is critical. Electroanalytical based sensors for ciprofloxacin have advantages over laboratory quantification methods, offering cost-effective, rapid, and portable sensing, which are also sensitive and selective. We chart the succession of electroanalytical methodologies directed toward the detection of ciprofloxacin, which starts off with mercury and then turns to using metal oxides, nanomaterials and finally molecular imprinted polymers. Within this perspective, we offer insights into future development in this field for the sensing of ciprofloxacin.

The first report of conductive recycled polyethylene terephthalate glycol (rPETg) for additive manufacturing and electrochemical applications is reported herein. Graphene nanoplatelets (GNP), multi-walled carbon nanotubes (MWCNT) and carbon black (CB) were embedded within a recycled feedstock to produce a filament with lower resistance than commercially available conductive polylactic acid (PLA). In addition to electrical conductivity, the rPETg was able to hold >10 wt% more conductive filler without the use of a plasticiser, showed enhanced temperature stability, had a higher modulus, improved chemical resistance, lowered levels of solution ingress, and could be sterilised in ethanol. Using a mix of carbon materials CB/MWCNT/GNP (25/2.5/2.5 wt%) the electrochemical performance of the rPETg filament was significantly enhanced, providing a heterogenous electrochemical rate constant, k0, equating to 0.88 (±0.01) × 10−3 cm s−1 compared to 0.46 (±0.02) × 10−3 cm s−1 for commercial conductive PLA. This work presents a paradigm shift within the use of additive manufacturing and electrochemistry, allowing the production of electrodes with enhanced electrical, chemical and mechanical properties, whilst improving the sustainability of the production through the use of recycled feedstock.

This review aims to provide an overview of sustainable approaches that can be incorporated into well-known procedures for the development of materials, pre- and post-treatments, modifications, and applications of 3D-printed objects, especially for fused filament fabrication (FFF). Different examples of conductive and non-conductive bespoke filaments using renewable biopolymers, bioplasticizers, and recycled materials are presented and discussed. The main final characteristics of the polymeric materials achieved according to the feedstock, preparation, extrusion, and treatments are also covered. In addition to recycling and remanufacturing, this review also explores other alternative approaches that can be adopted to enhance the sustainability of methods, aiming to produce efficient and environmentally friendly 3D printed products. Adjusting printing parameters and miniaturizing systems are also highlighted in this regard. All these recommended strategies are employed to minimize environmental damage, while also enabling the production of high-quality, economical materials and 3D printed systems. These efforts align with the principles of Green Chemistry, Sustainable Development Goals (SDGs), 3Rs (Reduce, Reuse, Recycle), and Circular Economy concepts.

Additive manufacturing (3D-printing), in particular fused filament fabrication, presents a potential paradigm shift in the way electrochemical based biosensing platforms are produced, giving rise to a new generation of personalized and on-demand biosensors. The use of additive manufactured biosensors is unparalleled giving rise to unique customization, facile miniaturization, ease of use, economical but yet, still providing sensitive and selective approaches towards the target analyte. In this mini review, we focus on the use of fused filament fabrication additive manufacturing technology alongside different biosensing approaches that exclusively use antibodies, enzymes and associated biosensing materials (mediators) providing an up-to-date overview with future considerations to expand the additive manufacturing biosensors field.

Among the existing metal-oxide gas sensors, cobalt oxide has the flexibility to revise the morphology through Cr-dopant to enhance sensing properties. Sensitive-surface of the chromium-doped cobalt oxide has proven its effective sensing nature to hydrogen sulfide gas. Interestingly, chromium-dopant increases the surface area, leading to particle size reduce and produces the more active sites for gas molecules. Also, the dopant creates impurity phases on the material which extends the sites for more reaction. To confirms these characteristics, the photoluminescence spectra showed intense peak that mimics the faster transport of electron to accelerate the sensing reaction. According to sensing measurement, the doped sensor is showing three-fold increase of response to 10 ppm gas and also, it detects the 2 ppm efficiently. The doped sensor warrants the stable response to gas due to higher reproducibility. Notably, the doped sensor detects the 1 ppm of gas at 120 s and recovery itself around 200 s. The doped sensor imparts response at room-temperature, affirming sensitive-surface. The doped sensor has shown the capable under humidity environment through response.