Anodization treatment of flexible graphite sheet electrodes for Nernstian pH sensing.

The ability to accurately determine pH in various complex matrix samples is important for understanding and managing various chemical environments. While glass pH probes are the standard for pH measurements, they present several drawbacks, including the need of frequent calibrations, and high susceptibility to interference from alkali metals. Herein, we demonstrate a voltammetric Nernstian pH sensing approach utilizing low-cost, flexible graphite sheet (GS) electrodes.

Additively Manufactured Electrodes for Simultaneous Detection of 2,4,6-Trinitrotoluene and Cyclotrimethylenetrinitramine in Postexplosive Residues and Environmental Samples.

This work reports the use of a custom-made filament based on polylactic acid and graphite to construct additively manufactured working electrodes, using fused filament fabrication 3D-printing technology, to simultaneously detect the explosives 2,4,6-trinitrotoluene (TNT) and cyclotrimethylenetrinitramine (RDX). We propose a simple strategy to increase detectability that consists of an electrochemical preconcentration step (-1.3 V Ag|AgCl|KCl for 30 s) to reduce RDX and TNT species on the 3D-printed electrode prior a single differential pulse stripping voltammetry scan in Britton-Robinson buffer (pH = 6.

Utilising highly conductive TPU "sticks" for facile and low-cost electroanalysis.

Rapid, on-site analysis of environmental contaminants necessitates the use of cost-effective and straightforward apparatus to encourage widespread adoption and align with the United Nations Sustainable Development Goal 6: Clean Water and Sanitation. In this work, we report the development of highly conductive thermoplastic polyurethane (TPU) filaments that can be easily cut and assembled into "sticks", functioning as standalone rod-like working electrodes for electrochemical and electroanalytical applications. Using TPU as the base polymer, filaments filled with 35, 40, and 45 wt% carbon black (CB) were fabricated and characterised both physicochemically and electrochemically at different lengths (2.

Enhancing fouling resistance of graphite sheets for electrochemical sensing of bisphenol-A.

Bisphenol A (BPA) is widely used in the production of polycarbonate plastics and epoxy resins, and it is now classified as an emerging pollutant due to its extensive environmental presence. Given the need for effective BPA monitoring, this study presents a cost-effective electrochemical approach for its quantification, using pyrolytic graphite sheets (GSs) as working electrodes integrated into a 3D-printed electrochemical cell. Despite initially exhibiting an intense voltammetric peak for BPA, fouling of the GS surface resulted in a progressive decrease in the BPA signal over successive scans.

Sustainable 3D-printing from coconut waste: conductive PLA-biochar filaments for environmental electrochemical sensing.

The integration of eco-friendly composites based on polymers and conductive fillers offers exciting opportunities for creating sustainable materials with superior electrical properties, paving the way for innovative advancements in electroanalytical devices. In this study, we explored the potential of biodegradable polylactic acid (PLA), carbon black (CB), and biochar derived from coconut shell waste to develop fused filament fabrication (FFF) filaments without the need for hazardous solvents. To assess the influence of biochar on the electrochemical properties, additional filaments composed exclusively of CB and PLA were also fabricated for comparison.

Artificial-Intelligence Bio-Inspired Peptide for Salivary Detection of SARS-CoV-2 in Electrochemical Biosensor Integrated with Machine Learning Algorithms.

Developing affordable, rapid, and accurate biosensors is essential for SARS-CoV-2 surveillance and early detection. We created a bio-inspired peptide, using the SAGAPEP AI platform, for COVID-19 salivary diagnostics via a portable electrochemical device coupled to Machine Learning algorithms. SAGAPEP enabled molecular docking simulations against the SARS-CoV-2 Spike protein's RBD, leading to the synthesis of Bio-Inspired Artificial Intelligence Peptide 1 (BIAI1).

Electrochemical Determination of Dipyrone Using a Cold-Plasma-Treated Graphite Sheet Electrode.

The development of fast, reliable, and cost-effective techniques for pharmaceutical compound analysis is an issue of paramount importance to the pharmaceutical industry, environmental sciences, and many other applications. In this work, a low-cost graphite sheet electrode (GSE) was used as a disposable working electrode. To this purpose, the GSE surface was subjected to a cold plasma discharge using a mixture of argon and O.

Low-cost and portable 3D-printed sensor for the determination of secnidazole in pharmaceutical and seized drug samples.

Additive manufacturing (3D printing), particularly fused deposition modeling (FDM), has rapidly advanced, offering customized designs, reduced waste, lower costs, and fast prototyping for electroanalytical applications. Herein, the electrochemical secnidazole (SCZ) behavior was studied using additive manufactured electrodes (AMEs) based on commercial carbon black and polylactic acid (PLA) conductive filament. Before use, AMEs were submitted to electrochemical/chemical activation (+1.

Laser-Induced Graphene for Electrochemical Sensing of Antioxidants in Biodiesel.

Synthetic antioxidants are often introduced to biodiesel to increase its oxidative stability, and -butyl hydroquinone (TBHQ) has been selected due to its high efficiency for this purpose. The monitoring of antioxidants in biodiesel therefore provides information on the oxidative stability of biodiesels. Herein, a laser-induced graphene (LIG) electrode is introduced as a new sensor for detecting -butyl hydroquinone (TBHQ) in biodiesel samples.

Additively manufactured ready-to-use platform using conductive recycled PLA for ketamine sensing.

The use of 3D-printed electrodes is reported fabricated from in-house conductive filament composed of a mixture of recycled poly (lactic acid) (rPLA), graphite (Gpt), and carbon black (CB) for fast detection of the abused drug ketamine. Firstly, the performance of these electrodes was evaluated in comparison to 3D-printed electrodes produced employing a commercially available conductive filament. After a simple pretreatment step (mechanical polishing), the new 3D-printed electrodes presented better performance than the electrodes produced from commercial filament in relation to peak-to-peak separation of the redox probe [Fe(CN)]/ (130 mV and 759 mV, respectively), charge transfer resistance (R = 1.

Bio-based plasticizer Babassu oil for custom-made conductive additive-manufacturing filaments: towards 3D-printed electrodes applied to cocaine detection.

Babassu (Atallea sp.), a native palm tree from South America's Amazon produces bio-oil and biochar with significant potential for industrial applications. Babassu oil as a bio-based plasticizer is reported here for the first time to replace petrochemical alternatives in the production of conductive filaments for additive manufacturing purposes.

Electroanalytical overview: the use of laser-induced graphene sensors.

Laser-induced graphene, which was first reported in 2014, involves the creation of graphene by using a laser to modify a polyimide surface. Since then, laser-induced graphene has been extensively studied for application in different scientific fields. One beneficial approach is the use of laser-induced graphene coupled with electrochemistry, where there is a growing need for disposable, conductive, reproducible, flexible, biocompatible, sustainable, and economical electrodes.

Electrochemical methods for the determination of acetaminophen in biological matrices: A critical review in the clinical field.

Background: Paracetamol or acetaminophen (APAP), or acetaminophen, is a widely used medication for pain relief and fever reduction due to its analgesic and antipyretic properties. However, excessive APAP consumption can lead to severe hepatotoxicity and nephrotoxicity, posing overdose risks. Consequently, the development of analytical methods for an accurate and rapid detection of APAP in biological matrices is of great interest in the health-related fields.

Electrochemical Immunosensors on Laser-Induced Graphene Platforms for Monitoring of Anti-RBD Antibodies After SARS-CoV-2 Infection.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has posed a major challenge to global health. The development of fast, accurate, and accessible diagnostic methods is essential in controlling the disease and mitigating its impacts. In this context, electrochemical biosensors present themselves as promising tools for the efficient monitoring of SARS-CoV-2 infection.

Tailoring 3D-printed sensor properties with reduced-graphene oxide: improved conductive filaments.

The development of a tailored filament is reported composed of reduced graphene oxide (rGO) and carbon black (CB) in a polylactic acid (PLA) matrix and its use in the production of electrochemical sensors. The electrodes containing rGO showed superior performance when compared with  those prepared in the absence of this material. Physicochemical and electrochemical characterizations of the electrodes showed the successful incorporation of both rGO and CB and an improved conductivity in the presence of rGO (lower resistance to charge transfer).

Portable Atmospheric Air Plasma Jet Pen for the Surface Treatment of Three-Dimensionally (3D)-Printed Electrodes.

Three-dimensional (3D) printing is an emerging technology to develop devices on a large scale with potential application for electroanalysis. However, 3D-printed electrodes, in their native form, provide poor electrochemical response due to the presence of a high percentage of thermoplastic polymer in the conductive filaments. Therefore, surface treatments are usually required to remove the nonconductive material from the 3D-printed electrode surfaces, providing a dramatic improvement in the electroanalytical performance.

3D-Printed Microdevices: From Design to Applications.

3D printing represents an emerging technology in several fields, including engineering, medicine, and chemistry [...

Gold film deposition by infrared laser photothermal treatment on 3D-printed electrodes: electrochemical performance enhancement and application.

3D printing has attracted the interest of researchers due to its creative freedom, low cost, and ease of operation. Because of these features, this technology has produced different types of electroanalytical platforms. Despite their popularity, the thermoplastic composites used for electrode fabrication typically have high electrical resistance, resulting in devices with poor electrochemical performance.

Rapid sequential determination of the explosives 2,4,6-trinitrotoluene and cyclotrimethylenetrinitramine in forensic samples employing a graphite sheet sensor and cyclic square-wave stripping voltammetry.

The development of a portable analytical procedure is described for rapid sequential detection and quantification of the explosives 2,4,6-trinitrotoluene (TNT) and cyclotrimethylenetrinitramine (RDX) in forensic samples using a graphite sheet (GS). A single GS platform works as a collector of explosive residues and detector after its assembly into a 3D-printed cell. The detection strategy is based on cyclic square-wave stripping voltammetry.

Lab-made CO laser-engraved electrochemical sensors for ivermectin determination.

The ivermectin (IVM), as a broad-spectrum antiparasitic drug, was widely prescribed to treat COVID-19 during the pandemic, despite lacking proven efficacy in combating this disease. Therefore, it is important to establish affordable devices in laboratories with minimal infrastructure. The laser engraving technology has been revolutionary in sensor manufacturing, primarily attributed to the diversity of substrates that can be employed and the freedom it provides in creating sensor models.

An innovative approach for selective and robust screening of NBOHs, NBOMes, and LSD in forensic samples using a 3D-Printed electrochemical double cell.

Lysergic acid diethylamide (LSD) and two phenethylamine classes (NBOHs and NBOMes) are the main illicit drugs found in seized blotter papers. The preliminary identification of these substances is of great interest for forensic analysis. In this context, this work constitutes the inaugural demonstration of an efficient methodology for the selective detection of LSD, NBOHs, and NBOMes, utilizing a fully 3D-printed electrochemical double cell (3D-EDC).

Novel disposable and portable 3D-printed electrochemical apparatus for fast and selective screening of 25E-NBOH in forensic samples.

The advent of new psychoactive substances (NPS) has caused enormous difficulty for legal control since they are rapidly commercialized, and their chemical structures are routinely altered. In this aspect, derivatives phenethylamines, such as 25E-NBOH, have received great attention in the forensic scenario. Hence, we propose portable and cost-effective (U$ 5.

CO-plasma surface treatment of graphite sheet electrodes for detection of chloramphenicol, ciprofloxacin and sulphanilamide.

Graphite sheet (GS) electrodes are flexible and versatile substrates for sensing electrochemical; however, their use has been limited to incorporate (bio)chemical modifiers. Herein, we demonstrated that a cold (low temperature) CO plasma treatment of GS electrodes provides a substantial improvement of the electrochemical activity of these electrodes due to the increased structural defects on the GS surface as revealed by Raman spectroscopy (I/I ratio), and scanning electron microscopy images. XPS analyses confirmed the formation of oxygenated functional groups at the GS surface after the plasma treatment that are intrinsically related to the substantial increase in the electron transfer coefficient (K values increased from 1.