Electroanalysis overview: additive manufactured biosensors using fused filament fabrication

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

Recycled PETg embedded with graphene, multi-walled carbon nanotubes and carbon black for high-performance conductive additive manufacturing feedstock

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

Electroanalysis overview: the determination of the poisoner's poison, thallium

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

Electroanalytical overview: the electroanalytical sensing of hydrazine

In this overview, we explore the electroanalytical sensing of the important chemical reagent hydrazine, highlighting the plethora of electrochemical sensing strategies utilised from the first reports in 1951 to the present day. It is observed that a large proportion of the work developing electrochemical sensors for hydrazine focus on the use of metallic nanoparticles and some other surface modifications, although we note that the advantages of such strategies are often not reported. The use of nanoparticle-modified electrodes to this end is explored thoroughly, indicating that they allow the same electrochemical response as that of a macroelectrode made of the same material, with clear cost advantages. It is recommended that significant studies exploring the surface coverage/number of nanoparticles are performed to optimise electroanalytical devices and ensure that thin-layer effects are not producing false observations through electrocatalysis. Development of these sensor platforms has begun to transition away from classical macroelectrodes, toward more mass producible supporting electrodes such as screen-printed and inkjet-printed electrodes. We suggest significant advances in this area are still to be found. The vast majority of developed electroanalytical sensors for hydrazine are tested in aqueous based environments, such as tap, river and industrial effluent waters. There is significant scope for development of hydrazine sensors for gaseous environments and biologically relevant samples such as blood, serum and urine, aiming to produce sensors for accurate occupational exposure monitoring. Finally, we suggest that the levels of publications with independent validation of hydrazine concentrations with other well-established laboratory-based measurements is lacking. We believe that improving in these areas will lead to the development of significant commercial products for the electroanalytical detection of hydrazine

Erratum to “Electroanalytical Overview: The detection of the molecule of murder atropine” [Talatan Open, 2021, 100073](S2666831921000436)(10.1016/j.talo.2021.100073)

The publisher regrets that the Conflict of interest was not published along with the manuscript. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The publisher would like to apologise for any inconvenience caused

Electroanalytical Overview: The Determination of Levodopa (L-DOPA)

L-DOPA (levodopa) is a therapeutic agent which is the most effective medication for treating Parkinson’s disease, but it needs dose optimization, and therefore its analytical determination is required. Laboratory analytical instruments can be routinely used to measure L-DOPA but are not always available in clinical settings and traditional research laboratories, and they also have slow result delivery times and high costs. The use of electroanalytical sensing overcomes these problems providing a highly sensitivity, low-cost, and readily portable solution. Consequently, we overview the electroanalytical determination of L-DOPA reported throughout the literature summarizing the endeavors toward sensing L-DOPA, and we offer insights into future research opportunities

Electroanalytical overview: the determination of manganese

Manganese is an essential nutrient of the human body but also toxic at elevated levels with symptoms of neurotoxicity reported, therefore its analytical determination is required. Manganese (II) is ingested primarily through food and drinking water so its routine monitoring in such samples is essential. While laboratory based analytical instrumentation can be routinely used to measure manganese (II), there is a need to develop methods for manganese (II) determination that can be performed in-the-field utilizing simple and inexpensive instrumentation yet providing comparable sensitive analytical measurements. Electrochemistry can provide a solution with instrumentation readily portable and hand-held coupled with electrochemical sensing platforms that are sensitive and provide on-site rapid analytical measurements. Consequently, in this overview we explore the electroanalytical determination of manganese (II) reported throughout the literature and offer insights into future research opportunities within this important field

Electroanalytical overview: utilising micro- and nano-dimensional sized materials in electrochemical-based biosensing platforms.

Research into electrochemical biosensors represents a significant portion of the large interdisciplinary field of biosensing. The drive to develop reliable, sensitive, and selective biosensing platforms for key environmental and medical biomarkers is ever expanding due to the current climate. This push for the detection of vital biomarkers at lower concentrations, with increased reliability, has necessitated the utilisation of micro- and nano-dimensional materials. There is a wide variety of nanomaterials available for exploration, all having unique sets of properties that help to enhance the performance of biosensors. In recent years, a large portion of research has focussed on combining these different materials to utilise the different properties in one sensor platform. This research has allowed biosensors to reach new levels of sensitivity, but we note that there is room for improvement in the reporting of this field. Numerous examples are published that report improvements in the biosensor performance through the mixing of multiple materials, but there is little discussion presented on why each nanomaterial is chosen and whether they synergise well together to warrant the inherent increase in production time and cost. Research into micro-nano materials is vital for the continued development of improved biosensing platforms, and further exploration into understanding their individual and synergistic properties will continue to push the area forward. It will continue to provide solutions for the global sensing requirements through the development of novel materials with beneficial properties, improved incorporation strategies for the materials, the combination of synergetic materials, and the reduction in cost of production of these nanomaterials

Additively manufactured rotating disk electrodes and experimental setup

This manuscript details the first report of a complete additively manufactured rotating disk electrode setup, highlighting how high-performing equipment can be designed and produced rapidly using additive manufacturing without compromising on performance. The additively manufactured rotating disk electrode system was printed using a predominantly acrylonitrile butadiene styrene (ABS) based filament and used widely available, low-cost electronics, and simplified machined parts to create. The additively manufactured rotating disk electrode system costs less than 2% of a comparable commercial solution (£84.47 ($102.26) total). The rotating disk electrode is also additively manufactured using a carbon black/polylactic acid (CB/PLA) equivalent, developing a completely additively manufactured rotating disk electrode system. The electrochemical characterization of the additively manufactured rotating disk electrode setup was performed using hexaamineruthenium(III) chloride and compared favorably with a commercial glassy carbon electrode. Finally, this work shows how the additively manufactured rotating disk electrode experimental system and additive manufactured electrodes can be utilized for the electroanalytical determination of levodopa, a drug used in the treatment of Parkinson's disease, producing a limit of detection of 0.23 ± 0.03 μM. This work represents a step-change in how additive manufacturing can be used in research, allowing the production of high-end equipment for hugely reduced costs, without compromising on performance. Utilizing additive manufacturing in this way could greatly enhance the research possibilities for less well-funded research groups

Electroanalytical overview: the sensing of hydroxylamine

One of the principal raw ingredients used in the manufacturing of pharmaceuticals, nuclear fuel, and semiconductors is hydroxylamine, a mutagenic and carcinogenic substance, ranking high on the list of environmental contaminants. Electrochemical methods for monitoring hydroxylamine have the advantage of being portable, quick, affordable, simple, sensitive, and selective enough to maintain adequate constraints in contrast with conventional yet laboratory based quantification methods. This review outlines the most recent advancements in electroanalysis directed toward the sensing of hydroxylamine. Potential future advancements in this field are also offered, along with a discussion of method validation and the use of such devices in real samples for the determination of hydroxylamine