Development of an Electrochemical Paper-Based Device Modified with Functionalized Biochar for the Screening of Paracetamol in Substandard Medicines.

The global prevalence of counterfeit and low-quality pharmaceuticals poses significant health risks and challenges in medical treatments, creating a need for rapid and reliable drug screening technologies. This study introduces a cost-effective electrochemical paper-based device (ePAD) modified with functionalized bamboo-derived biochar (BCF) for the detection of paracetamol in substandard medicines. The sensor was fabricated using a custom 3D-printed stencil in PLA, designed for efficient production, and a 60:40 (m/m) graphite (GR) and glass varnish (GV) conductive ink, resulting in a robust and sensitive platform.

Determination of Fluoxetine in Weight Loss Herbal Medicine Using an Electrochemical Sensor Based on rGO-CuNPs.

The rising popularity of herbal medicine as a weight loss remedy, fueled by misleading propaganda, raises concerns about the manufacturing processes and potential inclusion of controlled substances such as fluoxetine (FLU). The objective of this work is to develop and evaluate the performance of an electrochemical device by modifying a glassy carbon electrode (GC) with a nanocomposite based on reduced graphene oxide (rGO) and copper nanoparticles (CuNPs) for detecting FLU in manipulated herbal medicines. Scanning electron microscopy (FEG-SEM) and cyclic voltammetry (CV) were applied for morphological and electrochemical characterization and analysis of the composite's electrochemical behavior.

Copper Nanoparticles and Reduced Graphene Oxide as an Electrode Modifier for the Development of an Electrochemical Sensing Platform for Chloroquine Phosphate Determination.

This study describes the use of copper nanoparticles (CuNPs) and reduced graphene oxide (rGO) as an electrode modifier for the determination of chloroquine phosphate (CQP). The synthetized rGO-CuNPs composite was morphologically characterized using scanning electron microscopy and electrochemically characterized using cyclic voltammetry. The parameters were optimized and the developed electrochemical sensor was applied in the determination of CQP using square-wave voltammetry (SWV).

Acetylcholinesterase Biosensor Based on Functionalized Renewable Carbon Platform for Detection of Carbaryl in Food.

Enzymatic electrochemical biosensors play an important role in the agri-food sector due to the need to develop sustainable, low-cost, and easy-to-use analytical devices. Such biosensors can be used to monitor pathogens, endocrine disruptors, and pesticides, such as carbaryl, widely used in many crops. The use of renewable carbon (RC) sources, provided from biomass pyrolysis has been often applied in the fabrication of such sensors.

Fabrication of paper-based analytical devices using a PLA 3D-printed stencil for electrochemical determination of chloroquine and escitalopram.

Unlabelled: In recent years, the use of prescribed and non-prescribed drugs has increased. Therefore, advances in new technologies and sensors for detecting molecules in natural environments are required. In this work, a 3D-printed polylactic acid stencil is used to fabricate paper-based analytical devices (ePADs).

A Novel Method for the Detection of SARS-CoV-2 Based on Graphene-Impedimetric Immunosensor.

Due to the SARS-CoV-2 pandemic, there has been an increase in the search for affordable healthcare devices for mass testing and rapid diagnosis. In this context, this work described a new methodology for SARS-CoV-2 detection based on an impedimetric immunosensor developed using the advantageous immobilization of antibodies in the reduced graphene oxide (rGO). The rGO was obtained by chemical synthesis from the commercial graphene oxide (GO), and the materials were morphologically, electrochemically and visually characterized.

Shrinkage Stress and Temperature Variation in Resin Composites Cured via Different Photoactivation Methods: Insights for Standardisation of the Photopolymerisation.

The literature has shown that there is no consensus regarding the best resin composite photoactivation protocol. This study evaluated the efficiency of the conventional, soft-start, pulse-delay and exponential protocols for photoactivation of resin composites in reducing the shrinkage stress and temperature variation during the photopolymerisation. The photoactivation processes were performed using a photocuring unit and a smartphone app developed to control the irradiance according each photoactivation protocol.

Impacts of COVID-19 pandemic on the wastewater pathway into surface water: A review.

With global number of cases 106 million and death toll surpassing 2.3 million as of mid-February 2021, the COVID-19 pandemic is certainly one of the major threats that humankind have faced in modern history. As the scientific community navigates through the overwhelming avalanche of information on the multiple health impacts caused by the pandemic, new reports start to emerge on significant ancillary effects associated with the treatment of the virus.

Toxicity of cigarette butts and possible recycling solutions-a literature review.

Tobacco is a worldwide-consumed product, which in addition to causing public health-related issues is responsible for the most common form of litter in the world-smoked cigarette butts (CBs). A large attention has been drawn to this question, since this specific waste type tends to end up in terrestrial and aquatic ecosystems, posing serious threat to a range of life forms. Decomposition may take several years to occur because cellulose acetate is hardly accessible, before deacetylation, by bacteria and fungi.

Reduced Graphene Oxide-Based Impedimetric Immunosensor for Detection of Enterotoxin A in Milk Samples.

A simple, cheap, and less aggressive immobilization procedure for biomolecules using reduced graphene oxide (rGO) was employed to prepare an impedimetric immunosensor for detection of staphylococcal enterotoxin A (SEA) from in milk samples. The scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) were used to monitor the single steps of the electrode assembly process. The glassy carbon (GC)/rGO platform detected the antigen-antibody binding procedures of SEA with concentrations of 0.

Minimization of polymerization shrinkage effects on composite resins by the control of irradiance during the photoactivation process.

Introduction: High levels of shrinkage stress caused by volumetric variations during the activation process are one of the main problems in the practical application of composite resins.

Objective: The aim of this study is to reduce the shrinkage stress and minimize the effects caused by composite resin volumetric variation due to the photopolymerization. In this way, this work proposes a systematic study to determine the optimal dimming function to be applied to light curing processes.

Determination of serotonin on platinum electrode modified with carbon nanotubes/polypyrrole/silver nanoparticles nanohybrid.

A new sensor has been developed by a simple electrodeposition of multi-walled carbon nanotubes (MWCNT), polypyrrole (PPy) and colloidal silver nanoparticles on the platinum (Pt) electrode surface. The Pt/MWCNT/PPy/AgNPs electrode was applied to the detection of serotonin in plasmatic serum samples using differential pulse voltammetry (DPV). The synergistic effect of MWCNT/PPy/AgNPs nanohybrid formed yielded a LOD of 0.

Electrochemical detection of carbamate pesticides in fruit and vegetables with a biosensor based on acetylcholinesterase immobilised on a composite of polyaniline-carbon nanotubes.

A sensitive electrochemical acetylcholinesterase (AChE) biosensor was successfully developed on polyaniline (PANI) and multi-walled carbon nanotubes (MWCNTs) core-shell modified glassy carbon electrode (GC), and used to detect carbamate pesticides in fruit and vegetables (apple, broccoli and cabbage). The pesticide biosensors were applied in the detection of carbaryl and methomyl pesticides in food samples using chronoamperometry (CA). The GC/MWCNT/PANI/AChE biosensor exhibited detection limits of 1.

Glass/PDMS hybrid microfluidic device integrating vertically aligned SWCNTs to ultrasensitive electrochemical determinations.

This communication reports a promising platform for rapid, simple, direct, and ultrasensitive determination of serotonin. The method is related to integration of vertically aligned single-walled carbon nanotubes (SWCNTs) in electrochemical microfluidic devices. The required microfabrication protocol is simple and fast.

Evaluation of a carbon paste electrode modified with organofunctionalised SBA-15 nanostructured silica in the simultaneous determination of divalent lead, copper and mercury ions.

The performance of a carbon paste electrode (CPE) modified with SBA-15 nanostructured silica organofunctionalised with 2-benzothiazolethiol in the simultaneous determination of Pb(II), Cu(II) and Hg(II) ions in natural water and sugar cane spirit (cachaça) is described. Pb(II), Cu(II) and Hg(II) were pre-concentrated on the surface of the modified electrode by complexing with 2-benzothiazolethiol and reduced at a negative potential (-0.80 V).