Green Approach Research Articles

Assessment of the Effect of Surface Modification of Metal Oxides on Silver Nanoparticles: Optical Properties and Potential Toxicity.

Silver nanoparticles (AgNPs) have garnered significant interest due to their distinctive properties and potential applications. Traditional fabrication methods for nanoparticles often involve high-energy physical conditions and the use of toxic solvents. Various green synthesis approaches have been developed to circumvent these issues and produce environmentally benign nanoparticles. Our study focuses on the green synthesis of AgNPs using L-ascorbic acid and explores the modification of their properties to enhance antibacterial and anticancer effects. This is achieved by coating the nanoparticles with Zinc oxide (ZnO) and Silica oxide (SiO2), which alters their optical properties in the visible spectrum. The synthesized formulations-AgNPs, zinc oxide-silver nanoparticles (Ag@ZnO), and silica oxide-silver nanoparticles (Ag@SiO2) core/shell nanoparticles-were characterized using a suite of physicochemical techniques, including Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Zeta potential measurement, UV-Vis spectroscopy, Refractive Index Measurements, and Optical Anisotropy Assessment. TEM imaging revealed particle sizes of 11 nm for AgNPs, 8 nm for Ag@ZnO, and 400 nm for Ag@SiO2. The Zeta potential values for Ag@ZnO and Ag@SiO2 were measured at -17.0 ± 5 mV and -65.0 ± 8 mV, respectively. UV-Vis absorption spectra were recorded for all formulations in the 320 nm to 600 nm wavelength range. The refractive index of AgNPs at 404.7 nm was 1.34572, with slight shifts observed for Ag@ZnO and Ag@SiO2 to 1.34326 and 1.37378, respectively. The cytotoxicity of the nanocomposites against breast cancer cell lines (MCF-7) was assessed using the MTT assay. The results indicated that AgNPs and Ag@ZnO exhibited potent therapeutic effects, with IC50 values of 494.00 µg/mL and 430.00 µg/mL, respectively, compared to 4247.20 µg/mL for Ag@SiO2. Additionally, the antibacterial efficacy of AgNPs was significantly enhanced under visible light irradiation. Ag@ZnO demonstrated substantial antibacterial activity both with and without light exposure, while the Ag@SiO2 nanocomposites significantly reduced the inherent antibacterial activity of silver. Conversely, the Ag@ZnO nanocomposites displayed pronounced antibacterial and anticancer activities. The findings suggest that silver-based nanocomposites, particularly Ag@ZnO, could be practical tools in water treatment and the pharmaceutical industry due to their enhanced therapeutic properties.

A comparative and experimental study to evaluate the use of nanocontainer solutions for removing polymeric coatingsfrom glass artifacts

Purpose The purpose of this study is to evaluate the effectiveness of nanocontainer solutions in removing deteriorated and aged polymers commonly used in coating and consolidating archaeological glass. Design/methodology/approach This study focused on characterizing glass surfaces coated with two commonly used polymeric materials in archaeological glass preservation. Furthermore, the study evaluates the elimination of these coatings from the surfaces by using innovative aqueous systems composed of micellar solutions (MS) and oil-in-water (O/W) Texapon-P microemulsions (TEX). Glass samples coated with selected polymers were subjected to thermal and photochemical aging to simulate natural degradation conditions. This study aimed to evaluate the effectiveness of nanocontainer aqueous systems compared to acetone (Ac), a conventional solvent commonly used for removal procedures. The characterization procedures involved transmission electron microscopy, USB digital microscopy, scanning electron microscopy, color alteration and gravimetric measurement. Findings The findings indicate that the effectiveness of novel techniques using aqueous nanocontainer systems is quite promising when considering a “green approach” to preserving cultural heritage. Microscopic examination demonstrated the efficacy of MS in effectively removing acrylic and vinyl polymers from the glass surface. Furthermore, TEX proved effective in removing polyvinyl acetate (PVA) over Paraloid B72 (B-72). In addition, the measurement of color alteration values revealed a decrease after using MS compared to the standard sample before applying the polymers, with values of ΔE = 1.48 and 1.82 for B-72 polymer and PVA, respectively. Originality/value This research provides nanocontainer solutions for removing aged polymers from the glass surface. This makes the current study a promising step for treating archaeological glass.

A lab experiment on metals separation and recovery from waste ink-jet cartridges as a non-formal appealing learning activity for students of secondary schools

Abstract Since 2004, the Italian Ministry of Education, University and Research (MIUR), the Conference of Science and Technology Headmasters, and Confindustria, have been promoting the National Plan for Scientific Degrees (PLS) aimed at supporting students in acquiring scientific skills better responding to contemporary society challenges and increasing vocations in basic sciences. This paper describes a successful experience of the University of Cagliari together with selected local secondary schools, in which the hot topic of technological waste valorization was selected to create an orientation laboratory for students towards chemistry disciplines. Specifically, students and teachers were guided into the challenging world of e-waste production and treatment through the practical activity of noble metals recovery from real waste ink-jet cartridges. A specific emphasis was placed on fundamental chemical aspects – separation and recovery of metals driven by redox processes favored by a complexing agent – as well as on the chance to play on coordination chemistry to promote a green chemistry approach. The close collaboration between school and university teachers in planning and implementing laboratory activities is the element that characterizes PLS actions and promotes the development and strengthening of relations between secondary school and university courses in science, technology, engineering, and mathematics (STEM).

Electrochemical Sensor Modified with Graphene Oxide Decorated with Copper Oxide Nanoparticles for Velpatasvir’s Monitoring in Spiked Human Plasma.

Abstract Velpatasvir, an antiviral agent co-formulated with sofosbuvir used to treat hepatitis C, has recently demonstrated beneficial therapeutic effects against COVID-19. Therefore, therapeutic drug monitoring of velpatasvir is essential to achieve the desired clinical outcomes. An electrochemical sensor modified with synthesized copper oxide nanoparticles on the surface of graphene oxide (CuO/GO-NPs) was fabricated for the analysis of velpatasvir for the first time. Characterization was carried out using Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The voltammetric determinations were conducted using differential pulse and cyclic voltammetry, where the modified electrode exhibited better sensitivity than the unmodified one. The method was validated according to the International Council for Harmonisation (ICH) guidelines, exhibiting linearity within a range of 1.0 ×10-7 – 1.0 × 10-5 M, covering velpatasvir’s maximum plasma concentration (Cmax), with a quantification limit of 2.89 × 10-7 M and a detection limit of 9.03 × 10-8 M. The developed sensor was successfully applied to spiked human plasma at velpatasvir’s Cmax level. The method’s greenness was assessed using the Analytical Eco-scale and the Green analytical procedure index tools. This method holds promise as a green simple approach to implemented in future velpatasvir’s therapeutic drug monitoring studies.

Regulating the Topology of Covalent Organic Frameworks for Boosting Overall H2O2 Photogeneration

AbstractPhotocatalytic oxygen reduction reactions and water oxidation reactions are extremely promising green approaches for massive H2O2 production. Nonetheless, constructing effective photocatalysts for H2O2 generation is critical and still challenging. Since the network topology has significant impacts on the electronic properties of two dimensional (2D) polymers, herein, for the first time, we regulated the H2O2 photosynthetic activity of 2D covalent organic frameworks (COFs) by topology. Through designing the linking sites of the monomers, we synthesized a pair of novel COFs with similar chemical components on the backbones but distinct topologies. Without sacrificial agents, TBD‐COF with cpt topology exhibited superior H2O2 photoproduction performance (6085 and 5448 μmol g−1 h−1 in O2 and air) than TBC‐COF with hcb topology through the O2‐O2⋅−‐H2O2, O2‐O2⋅−‐O21‐H2O2, and H2O‐H2O2 three paths. Further experimental and theoretical investigations confirmed that during the H2O2 photosynthetic process, the charge carrier separation efficiency, O2⋅− generation and conversion, and the energy barrier of the rate determination steps in the three channels, related to the formation of *OOH, *O21, and *OH, can be well tuned by the topology of COFs. The current study enlightens the fabrication of high‐performance photocatalysts for H2O2 production by topological structure modulation.

Electro‐Oxidation of Alkenes: A Green Approach Towards Functionalized Oxygenates

In chemical industrial process, conversion of alkenes to functional oxygenates plays a key role in bridging between the feedstock and downstream application. Traditionally, the oxidation required highly‐active oxygen sources or molecular oxygen under high temperature and pressure. This poses challenges to the green and safe production of oxygenates. To circumvent the issues of massive consumption of fossil fuel and serious CO2 footprints, approaches of electro‐oxidation are developed under ambient conditions, adopting O2 and H2O as oxygen source. Utilizing electricity from renewable resources and the involved electron transfer, the performance is closely related to the interface characteristics of electrodes and electrolytes. This review presents the progress in catalysts design, electrolytes optimization, cells integration to effectively regulate the microenvironment of the interfaces. Further discussion of the mechanism analysis and potential issues are emphasized, based on the in‐situ characterization techniques, isotopic experiments and quenching tests. We hope this review can provide an outline for green approaches to oxidation of alkenes via electrocatalytic pathways.

In-silico green toxicology approach toward discovering safer ligands for development of safe-by-design metal organic frameworks

: A vast variety of chemical compounds have been fabricated and commercialized, they not only result in industrial exposure during manufacturing and usage, but also have environmental impacts throughout their whole life cycle. Consequently, attempts to assess the risk of chemicals in terms of toxicology have never ceased. In-silico toxicology, also known as predictive toxicology, has advanced significantly over the last decade as a result of the drawbacks of experimental investigations. In this study, ProTox-III was applied to predict the toxicity of the ligands used for metal organic framework design and synthesis. Initially, 35 ligands, that have been frequently utilized for MOF synthesis and fabrication, were selected. Subsequently, canonical SMILES of ligands were extracted from the PUBCHEM database and inserted into the ProTox-III online server. Ultimately, webserver outputs including LD50 and the probability of toxicological endpoints (cytotoxicity, carcinogenicity, mutagenicity, immunotoxicity and ecotoxicity) were obtained and organized. According to retrieved LD50 data, the safest ligand was 5-hydroxyisophthalic. In contrast, the most hazardous ligand was 5-chlorobenzimidazole, with an LD50 of 8 mg/kg. Among evaluated endpoints, ecotoxicity was the most active and was detected in several imidazolate ligands. This data can open new horizons in design and development of green MOFs.

Green Synthesis of Bioplastics from Microalgae: A State-of-the-Art Review

The synthesis of conventional plastics has increased tremendously in the last decades due to rapid industrialization, population growth, and advancement in the use of modern technologies. However, overuse of these fossil fuel-based plastics has resulted in serious environmental and health hazards by causing pollution, global warming, etc. Therefore, the use of microalgae as a feedstock is a promising, green, and sustainable approach for the production of biobased plastics. Various biopolymers, such as polyhydroxybutyrate, polyurethane, polylactic acid, cellulose-based polymers, starch-based polymers, and protein-based polymers, can be produced from different strains of microalgae under varying culture conditions. Different techniques, including genetic engineering, metabolic engineering, the use of photobioreactors, response surface methodology, and artificial intelligence, are used to alter and improve microalgae stocks for the commercial synthesis of bioplastics at lower costs. In comparison to conventional plastics, these biobased plastics are biodegradable, biocompatible, recyclable, non-toxic, eco-friendly, and sustainable, with robust mechanical and thermoplastic properties. In addition, the bioplastics are suitable for a plethora of applications in the agriculture, construction, healthcare, electrical and electronics, and packaging industries. Thus, this review focuses on techniques for the production of biopolymers and bioplastics from microalgae. In addition, it discusses innovative and efficient strategies for large-scale bioplastic production while also providing insights into the life cycle assessment, end-of-life, and applications of bioplastics. Furthermore, some challenges affecting industrial scale bioplastics production and recommendations for future research are provided.

Green Chemistry Approach for One‐Step Synthesis of Iodinated Graphene Material for Supercapacitor Applications

AbstractIodinated graphene is a promising 2D material with unique physical and chemical characteristics. A new synthesis method that combines iodine intercalation and surface reduction of graphite sheets in a single step was developed. This method uses NaIO4 and m‐CPBA to efficiently incorporate iodine and selectively remove oxygen from the graphene network at room temperature. The presence of iodine moieties in the graphene network was confirmed using various techniques such as XPS photoelectron spectroscopy, HR‐TEM, XRD, FT‐IR, TGA, and Raman spectroscopy. The high iodine content of the material enhanced the d‐spacing and ion mobility of the electrolyte, thereby improving the storage capacity. In addition, the potential of iodinated graphene as an electrode material was investigated through EIS, CV, and GCD using 1 M H2SO4 solution as the electrolyte. The iodinated graphene material exhibited EDL capacitance and demonstrated an impressive specific capacitance of 535.4 F g−1 at a high rate, with a current density of 1 A g−1. Moreover, it exhibited exceptional stability over 5000 cycles. These halogenated graphene derivatives are attractive options for use in supercapacitors.

Viscose fibers decorated with silver nanoparticles via an in-situ green route: UV protection, antioxidant activities, antimicrobial properties, and sensing response

AbstractMultifunctional cellulosic fibers are in high demand for use in a variety of applications. Functional cellulosic fibers obtained through green and sustainable approaches are getting special attention because of the need to limit the environmental impact of hazardous chemicals. Herein, a novel facile, efficient, and eco-friendly approach for multifunctional viscose fibers@Ag NPs (VF-Ag) was designed by a rapid, facile, and one-pot biosynthesis green route using guava leaf extract as a reducing and stabilizing agent. UV–Vis, TEM, SEM, EDX, FTIR, and XPS were used to analyze the formation of silver nanoparticles and their subsequent deposition on the surface of viscose fibers. The silver nanoparticles immobilized on the surface of viscose fibers endowed a yellow/brownish color to the fibers as well as improving the dyeing with reactive dye. The VF-Ag samples have multifunctional properties like protective activities against UV radiation and microorganisms, antioxidant activity, and sensor ability toward Hg2+. The results demonstrated that the UPF values of VF-Ag samples ranged from 280 to 355 compared to 103 for VF. The antioxidant activities of VF-Ag ranged from 79 to 85% compared to 9% for VF. VF-Ag samples exhibited excellent antimicrobial activities against Gram-positive and Gram-negative bacteria, very good activities against yeast, and low activities against fungus.VF and VF-Ag were dyed using reactive dye (CI-reactive blue-19) at two color intensities (2.5, and 5%). The results show that the color of VF turned blue, while the color of VF-Ag turned greenish. The color strength of VF-Ag significantly increased with increasing silver content. Furthermore, VF-Ag showed high sensitivity to naked-eye colorimetric sensing for the detection of Hg2+. In straightforward, this innovative approach provides an easy, quick, and low-cost that will open the door for a range of versatile applications for modified viscose fibers in the fields of medical and analytical applications.

Enhancement of microplastics degradation with MIL-101 modified BiOI photocatalyst under light and dark alternated system

The composite material combining BiOI with metal-organic frameworks, was developed as catalyst for microplastics degradation. The preparation was modified to achieve the optimal composite catalyst BiOI/MIL-101–40%. The composites exhibited a larger surface area, superior photo-activity, and a distinct heterojunction structure, which accelerated the separation of electrons and holes. Besides, the inclusion of Fe(II) within MIL-101 could construct a photo-Fenton reaction upon the addition of H2O2 in the solution. The carbonyl index of treated polyethylene microplastics increased by 0.127 after 6 h reaction, which was 5.3 and 3.7 times higher than monomer BiOI and MIL-101, respectively. Efficient electron-hole separation and Fe(III)/Fe(II) conversion improved the rate-limiting step of the Fenton process, leading to a synergistic effect between photocatalysis and Fenton reaction, significantly enhancing PE degradation efficiency. Electron spin resonance spectroscopy and selective radical quenching experiments were performed to detect the active components, and the main active species proved to be the hydroxyl radical and the hole. The band structure of the photocatalyst and intermediate products in the reaction solution were subsequently analyzed, leading to the inference of potential reaction mechanisms and pathways. The catalyst-built Fenton system demonstrated outstanding proficiency even under alternating light and dark conditions. The extracted microplastic samples also confirmed the feasibility of this system for complex samples. In conclusion, this study highlighted a green and efficient approach that may be used in future industrial applications to combat microplastic pollution.

Conventional to “Go Green” Approach in Organic Reaction

In the recent times, the green method of chemical reactions becomes very popular. The scientists are now using the non–hazardous reagents and solvents to design a chemical reaction. The conventional method of most common organic rearrangements e.g Claisen, Fries etc and condensation reactions e.g Aldol, Benzoin, Knoevenegal etc. are designed successfully in greener approach. This article describes green approach of some of these reactions.

Enzymes-based nanomaterial synthesis: an eco-friendly and green synthesis approach

Enzymes-based nanomaterial synthesis: an eco-friendly and green synthesis approach

Antibacterial efficacy of Rumex dentatus leaf extract-enriched zinc oxide and iron doped zinc nanoparticles: a comparative study

In the current investigation, zinc oxide (ZnO) nanoparticles and Fe-doped ZnO nanoparticles were sustainably synthesized utilizing an extract derived from the Rumex dentatus plant through a green synthesis approach. The Scanning electron microscope (SEM), X-ray diffraction (XRD), Energy-dispersive x-ray spectroscopy (EDX), Ultra-violet visible spectroscopy (UV–vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA) techniques were used to examine the compositional, morphological, optical, and thermal properties of both samples. The doping of iron into ZnO NPs has significantly influenced their properties. The analysis firmly established that both ZnO NPs and Fe-doped ZnO NPs have hexagonal wurtzite structures and spherical shapes by XRD and SEM. The EDX analysis suggests that iron atoms have been successfully integrated into the ZnO lattice. The change in color observed during the reaction indicated the formation of nanoparticles. The UV–vis peaks at 364 nm and 314 nm confirmed the presence of ZnO NPs and Fe-doped ZnO NPs, respectively. The band gap of ZnO NPs by Fe dopant displayed a narrowing effect. This indicates that adding iron ions to ZnO NPs offers a control band gap. The thermal study TGA revealed that Fe-doped ZnO NPs remain stable when heated up to 600 °C. The antibacterial efficacy of ZnO NPs and Fe-doped ZnO NPs was evaluated against several bacterial strains. The evaluation is based on the zone of inhibition (ZOI). Both samples exhibited excellent antibacterial properties as compared to conventional pharmaceutical agents. These results suggest that synthesizing nanoparticles through plant-based methods is a promising approach to creating versatile and environmentally friendly biomedical products.

A new green approach to L-histidine and β-alanine analysis in dietary supplements using rapid and simple contactless conductivity detection integrated with high-resolution glass-microchip electrophoresis.

The analysis of dietary supplements is far less regulated than pharmaceuticals, leading to potential quality issues. Considering their positive effect, many athletes consume supplements containing L-histidine and β-alanine. A new microfluidic method for the determination of L-histidine and β-alanine in dietary supplement formulations has been developed. For the first time, capacitively coupled contactless conductivity detection was employed for the microchip electrophoresis of amino acids in real samples. A linear relationship between detector response and concentration was observed in the range of 10-100µmol L-1 for L-histidine (R2 = 0.9968) and β-alanine (R2 = 0.9954), while achieved limits of detection (3 × S/N ratio) were 4.2µmol L-1 and 5.2µmol L-1, respectively. The accuracy of the method was confirmed using recovery experiments as well as CE-UV-VIS and HPLC-UV-VIS techniques. The developed method allows unambiguous identification of amino acids in native form without chemical derivatization and with the possibility of simultaneous analysis of amino acids with metal cations.

Maize leaves as a precursor for the synthesis of greened silver nanocomposite and nanoparticles

This study is aimed at the synthesis of nanoparticles (NPs) and nanocomposite (NC) using maize leave as precursor. Silver NPs (AgNPs) and AgNCs were synthesized from silver nitrate and maize leave extract using green approach. The maize leave NPs (AgNPs) and the maize leave NCs (AgNCs) were characterized using Fourier Transform infrared (FTIR), scanning electron microscopy (SEM), energy dispersion x-ray (EDX), Brunauer–Emmett–Teller (BET) surface area measurement, and dynamic light scattering (DLS) particle size analysis. The phytochemical analysis revealed the presence of tannin, oxalate, and flavonoids in appreciable quantity, which have proven to be a powerful reducing agent that facilitates the reduction of silver ions for the synthesis of silver NPs and silver nano composites. FTIR revealed that all the peaks identified in AgNPs and AgNCs belong to the characteristic bands of reducing compounds such as flavonoid compounds. The SEM-EDX results showed that the peaks observed from 2.9 to 3.1 Kev in the spectra indicate the presence of elemental silver as it is reduced from Ag+ to Ag. DLS analysis results showed that the average size and polydispersity index (PdI) of the synthesized AgNPs and AgNCs were 42.30 and 68.29 nm, 0.691 and 0.270, respectively. The single point BET surface area (m2/g) obtained for AgNPs and AgNCs were 223.3 and 209.5, respectively. The results showed maize leave as a potential precursor for the preparation of NPs and NCs.

Microwave‐Assisted Preparation of an Acidic Deep Eutectic Solvent: Green Analysis, Characterization and Application

AbstractMicrowave irradiation was postulated to reduce time and energy for deep eutectic solvent (DES) production which is in line with the principle of green chemistry. In this study, the choline chloride (ChCl)‐malic acid (MA) DES was prepared using microwave‐assisted (DES‐Mic) and conventional (DES‐Con) approaches. Microwave was a relatively greener approach as it was rapid (5 min) and consumed 92.8 % energy less than DES‐Con. Moreover, DES‐Mic and DES‐Con exhibited similar physicochemical profiles (pH, solubility, density) and rheological properties. Structural profiling through FTIR analysis suggested hydrogen bond formation between the functional groups of ChCl and MA. The FTIR spectra also did not show structural differences in the DES synthesized using different methods. DES‐Mic and DES‐Con exhibited superior 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) (80.8±0.1 and 83.2±0.3 %, respectively) free radical scavenging activities than ChCl (15.6±0.8 %), MA (20.0±1.4 %) and ChCl:MA aqueous mixture without subjected to DES synthesis conditions (ChCl:MAaq; 23.3±0.8 %). Both DES were also proven as more efficient solvents for the extraction of polysaccharides from ramie leaf, as they recorded higher yields (21.4±1.9 and 22.2±1.0 %, respectively) than equimolar of MA (17.7±2.6 %) and ChCl (6.4±0.2 %). Overall, microwave was proven as a more sustainable approach for DES preparation compared to conventional method, which could be further improvised for industrial applications.

Network pharmacology speaking to ethnopharmacology: new data on an ancient remedy

Network pharmacology as a “green approach”, predicting metabolite behaviours chemically and biologically and guid¬ing biological experimental design, is a new strategy aiming to uncover the mechanism of action of natural products as drug candidates. It provides a powerful way to identify novel mechanisms of natural products with potential thera¬peutic effects. This approach has emerged as a powerful tool to overcome the limitations of traditional methods, such as the ability to predict the adverse effects of a drug and the likelihood of failure during clinical trials, by applying systems biology principles to the field of pharmacology. This method combines the multi-omics dataset, computer modeling, and chemical biology so as to reveal pharmaceutical actions and guide drug discovery. Therefore, computer-aided drug design combined with network pharmacology can be viewed as a novel in silico screening ap¬proach to drug discovery, by utilising chemoinformatics, bioinformatics, structure biology, and chemical biology. This strategy includes target-based virtual screening - molecular docking, ligand similarity-based virtual screening, and inverse screening (Inver-dock), providing a powerful tool for target identification of drug candidates, multitarget dis¬covery, and natural bioactive product profiling. It can also be used for selectivity profiling of drugs, drug repositioning, safety profiling, and metabolism profiling prediction (ADMET).

Semi-continuous cultivation of EPS-producing marine cyanobacteria: A green biotechnology to remove dissolved metals obtaining metal-organic materials

Given the necessity for bioprocesses scaling-up, the present study aims to explore the potential of three marine cyanobacteria and a consortium, cultivated in semi-continuous mode, as a green approach for i) continuous exopolysaccharide-rich biomass production and ii) removal of positively charged metals (Cu, Ni, Zn) from mono and multi-metallic solutions. To ensure the effectiveness of both cellular and released exopolysaccharides, weekly harvested whole cultures were confined in dialysis tubings. The results revealed that all the tested cyanobacteria have a stronger affinity towards Cu in mono and three-metal systems. Despite the amount of metals removed per gram of biomass decreased with higher biosorbent dosage, the more soluble carbohydrates were produced, the greater was the metal uptake, underscoring the pivotal role of released exopolysaccharides in metal biosorption. According to this, Dactylococcopsis salina 16Som2 showed the highest carbohydrate productivity (142 mg L−1 d−1) and metal uptake (84 mg Cu g−1 biomass) representing a promising candidate for further studies. The semi-continuous cultivation of marine cyanobacteria here reported assures a schedulable production of exopolysaccharide-rich biosorbents with high metal removal and recovery potential, even from multi-metallic solutions, as a step forward in the industrial application of cyanobacteria.

Eco-friendly fabrication of silver nanoparticle-decorated electrodes for aqueous bisphenol A sensing

This work fabricated an electrochemical sensor for detecting bisphenol A (BPA) by employing silver nanoparticles (AgNPs) synthesized through an eco-friendly approach. The AgNPs were produced using parsley leaf extract, which acted as a reducing and stabilizing agent in the synthesis process. The AgNPs synthesized using the green approach exhibited an average size of 15.2 ± 2.1 nm. The AgNP-modified screen-printed electrode (SPE) exhibited excellent electrocatalytic activity towards BPA oxidation, with an enhanced peak current of 28.6 μA compared to 5.2 μA for the bare SPE. The optimized sensor exhibited impressive analytical performance, boasting a broad linear range spanning 0.05–5 μM for BPA detection. Remarkably, it achieved a low limit of detection of 0.02 μM, coupled with high sensitivity. Furthermore, the sensor demonstrated commendable reproducibility, with a RSD of 3.6%, and exceptional repeatability, evidenced by an RSD of 2.4%. Upon evaluating the sensor's performance in analyzing real water specimens, the recoveries oscillated between 95.8% and 103.5%, accompanied by RSDs not exceeding 4.2%, thereby demonstrating its successful application for BPA detection. The eco-friendly synthesis approach and superior analytical performance make the AgNP-modified SPE a promising tool for on-site environmental monitoring and drinking water analysis.