Emerging viruses are a major public health problem. Most zoonotic pathogens originate in wildlife, including human immunodeficiency virus (HIV), influenza, Ebola, and coronavirus. Severe acute ...respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus called SARS-associated coronavirus (SARS-CoV). Viruses are charged colloidal particles that have the ability to adsorb on surfaces depending on pH. Their sorptive interaction with solid particles has important implications for their behavior in aquatic environments, soils, sewage sludge, and other solid materials and their removal or concentration by water treatment processes.
Current state of knowledge on the potential of wastewater surveillance to understand the COVID-19 pandemic is reviewed. This study also identified wastewater irrigation systems with a higher risk of COVID-19 transmission. Emphasis was placed on methodologies for the detection and quantification of SARS-CoV-2 in wastewater.
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•Evidence for the presence of COVID-19 in wastewater•Detection methods and prevalence of viruses in wastewater•Knowledge needs for public health.•Recommendations on research and investigation priorities
•Methods of green synthesis of (NPs) using plant extract were reviewed.•Properties and characterization techniques of nanoparticles were presented.•Shape and size of green synthesized (NPs) via each ...plant have been compared.•Different utilizations of green synthesized (NPs) were inspected.•Future viewpoint of utilizations of green synthesis of (NPs) was studied.
The Nano-biotechnology represents the intersection of nanotechnology and biotechnology and is a promising field of nanotechnology. Recently, the need of making biocompatible nanoparticles for different applications in various areas by eco-friendly technologies in materials science became significant. Today, green synthesis of different nanoparticles NPs has been broadly examined. Biological synthesis of nanoparticles has evolved as a promising substitute to traditional synthesis methods for producing nanoparticles using unicellular and multicellular biological entities such as actinomycetes yeast, bacteria, viruses, plants, and fungus. In this paper, we provide a general overview on properties, synthesis methods and applications of nanoparticles NPs prepared from plant extract. Indeed, different techniques of green synthesis of NPs by plant extract were discussed and presented. The properties of synthesized NPs, in particular shape and size, were discussed and their applications have been also investigated. Furthermore, the future perspective of green synthesis of NPs and their applications were expressed.
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•Electrochemical detection of amoxicillin (AMX)•Types of chemically modified electrodes for AMX detection.•Indirect electrochemical methods for AMX analysis.•Analysis of Amoxicilin in ...several real samples.
Amoxicillin (AMX) is among the most successful antibiotics used for human therapy. It is used extensively to prevent or treat bacterial infections in humans and animals. However, the widespread distribution and excess utilization of AMX can be an environmental and health risk due to the hazardous potential associated to its pharmaceutical industries effluents. Besides, their extensive use in food animal production may result in some undesirable residues in food, e.g. meat, eggs and milk. Consequently, at high enough concentrations in biological fluids, AMX may be responsible of various diseases such as nausea, vomiting, rashes, and antibiotic-associated colitis. For this reason, the detection and quantification of amoxicillin in pharmaceuticals, biological fluids, environmental samples and foodstuffs require new electroanalytical techniques with sensitive and rapid measurement abilities. This review discusses recent advances in the development of electrochemical sensors and bio-sensors for AMX analysis in complex matrices such as pharmaceuticals, biological fluids, environmental water and foodstuffs. The main electrochemical sensors used are based on chemically modified electrodes involving carbon materials and nanomaterials, nanoparticles, polymers and biological recognition molecules.
This paper reports on the fabrication of material comprised of chitosan stabilized silver nanoparticles on the carbon paste and its electro-catalytic reduction toward 4-nitroaniline. The synthesized ...material was obtained when AgNO3 was mixed with chitosan as a stabilizing agent and NaBH4 as a reducing agent. The developed Chitosan-AgNPs has been confirmed using UV–Vis spectroscopy, X-Ray diffraction analysis, scanning electron microscopy (SEM) and infrared spectroscopy. The synthesized chitosan-Ag NPs exhibit particle size around 51 nm. To build a voltammetric sensor (Chitosan-Ag NPs/CPE), a carbon paste electrode has immersed in the liquid suspension of chitosan-Ag NPs, thus, it could be employed for electro-catalytic reduction of 4-NA in 0.1 M Britton-Robinson buffer solution (B-R, pH 2). Therefore, the reduction over-potential of 4-NA shifted from −752.26 mV at CPE to −304 mV at chitosan-Ag NPs/CPE, and then showing a surface controlled process with the catalytic rate constant (Kcat) of 0.125 × 10−3 M−1 s−1 and a coefficient of diffusion (D) of 2.20 × 10−6 cm2 s−1 with an enhanced current response. Under optimized conditions, the electro-catalytic reduction peak current of 4-NA increased linearly with increasing of 4-NA concentration over the range of 1 μM to 0.5 mM (R2 = 0.9866) with a detection limit of 0.86 μM (3 × Sb/P).
•CS@Ag/CPE has excellent electrocatalytic activity toward p-NA reduction.•The catalytic effect was studied using cyclic voltammetry and chronoamperometry.•All parameters affecting the detection of p-nitroaniline were optimized.•The results indicated the efficiency of proposed electrode to determine p-NA using DPV.
The purpose of this paper is to fabricate graphene oxide (GO) from carbon rods of spent (ZnC) batteries using a new optimized approach in electrochemical applications. The proposed method-based ...sonication for the recycling of carbon rods was adopted as a fast and economical process via a less aggressive pathway. The energy reaction time and explosion problems were avoided by the proposed protocol. The waste graphite powder (carbon rods) and the powder produced by the developed method-based sonication (SGO) were characterized by UV–Visible, XRD, FTIR and SEM. The electrochemical performance of the prepared SGO was evaluated by cyclic voltammetry (CV) and current-voltage (I–V) techniques. The results revealed that SGO has a higher electrocatalytic property compared to the graphene oxide by the standard Hummers method (HGO).
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∙Sonication-assisted oxidation and exfoliation process was recycled for graphene oxide (SGO) production.∙The carbon powder of (ZnC) batteries rods and its graphene oxide (SGO) were characterized.∙The energy and reaction time along with explosion problems were avoided by the proposed approach.∙Electrochemical performances of SGO were investigated and compared to the Hummers graphene oxide (HGO).
The behavior of a modified carbon paste electrode (CPE) for
para-nitrophenol detection by cyclic and square wave voltammetry (SWV) was studied. The electrode was built by incorporating the ...hydroxyapatite (HAP) to carbon paste. The overall analysis involved a two-step procedure: an accumulation step at open circuit, followed by medium exchange to a pure electrolyte solution for the voltammetric quantification. During the preconcentration step,
para-nitrophenol was adsorbed onto hydroxyapatite surface. The influence of various experimental parameters on the HAP–CPE response was investigated (i.e. pH, carbon paste composition, accumulation time). Under the optimized conditions, the reduction peak shows that the peak height was found to be directly proportional to the
para-nitrophenol concentration in the range comprised between 2
×
10
−7
mol
L
−1 and 1
×
10
−4
mol
L
−1. With this, it was possible to determine detection limit (DL), which resulted in 8
×
10
−9
mol
L
−1 for peak 1. The proposed electrode (HAP–CPE) presented good repeatability, evaluated in term of relative standard deviation (R.S.D.
=
2.87%) for
n
=
7 and was applied for
para-nitrophenol determination in water samples. The average recovery for these samples was 86.2%.
Nickel oxide doped natural phosphate (NP/NiO) nanoparticles were thermally synthesized for effective adsorption of Reactive Red 141 (RR141) as toxic dye model, characterization methods such as X-ray ...diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy combined with energy dispersive X-ray analysis(SEM-EDAX)and have been employed to identify the adsorbent. Surface area and pore size volume were determined by the Brunauer, Emmett and Teller (BET) method. Environmental factors such as pH, time of contact, initial RR141 concentration, the dose of adsorbent and solution temperature have been all put to the test to evaluate optimum adsorption activity. Thermal processing NP/NiO at 1% NiO doping percentage was effectual for exhibiting best adsorption behavior at an annealing temperature of 600 °C. Furthermore, batch experiments revealed significant adsorption activity reaching 96%. The maximal adsorption capacity was found to be 38.91 mg of RR 141 per 0.1 g of the adsorbent in only 40min of contact, at an initial colorant concentration of 20 mg L−1, pH 6 at ambient temperature and a volume of 100 ml. Langmuir isotherm model was more adequate to describe the adsorption process than the Freundlich model. The rate mechanism of the adsorption process was determined from the intraparticle diffusion model, Boyd plot revealed that the adsorption of the dye on the NP/NiO was mainly governed by film diffusion. Moreover, the dye adsorption was spontaneous and exothermic. The mechanism of adsorption may involve chemical adsorption through hydrogen bonding mechanism and electrostatic interactions between the dye molecules and the adsorbent. Thermal regeneration was feasible only for three cycles, the adsorbent also showed great potential for real textile wastewater treatment.
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•Natural phosphate doped nickel oxide (NP/NiO) was thermally synthesized.•NP/NiO was successfully applied in the removal of Reactive Red 141 anionic dye.•Maximum adsorption percentage reached in optimal conditions was 96%.•Two adsorption mechanisms involved; hydrogen bonding and electrostatic interactions.
•COVID-19 infection poses a serious risk to human life by causing acute lung damage.•Various techniques used to identify and quantify COVID-19 infection.•Major challenges for containing the spread of ...COVID-19 is the ability to identify asymptomatic cases.•Currently available diagnostic methods, biosensing technology developed during COVID-19 infection.
The technologies used for coronavirus testing consist of a pre-existing device developed to examine different pathologies, such as bacterial infections, or cancer biomarkers. However, for the 2019 pandemic, researchers knew that their technology could be modified to detect a low viral load at an early stage. Today, countries around the world are working to control the new coronavirus disease (n-SARS-CoV-2). From this perspective, laboratories, universities, and companies around the world have embarked on a race to develop and produce much-needed test kits. This review has been developed to provide an overview of current trends and strategies in n-SARS-CoV-2 diagnostics based on traditional and new emerging assessment technologies, to continuous innovation. It focuses on recent trends in biosensors to build a fast, reliable, more sensitive, accessible, user-friendly system and easily adaptable technology n-SARS-CoV-2 detection and monitoring. On the whole, we have addressed and identified research evidence supporting the use of biosensors on the premise that screening people for n-SARS-CoV-2 is the best way to contain its spread.
The widespread use of antibiotics has contributed to the control of disease and the nutritional well-being of livestock. Antibiotics reach the environment via excretions (urine and feces) from human ...and domestic animals, through non proper disposal or handling of unused drugs. The present study describes a green method for the synthesis of silver nanoparticle (AgNPs) using cellulose extracted from Phoenix dactylifera seed powder via mechanical stirrer method for the electroanalytical determination of ornidazole (ODZ) in milk and water samples. The cellulose extract is used as the reducing and stabilizer agent for the synthesis of AgNPs. The obtained AgNPs were characterized by UV–Vis, SEM and EDX, presenting a spherical shape and an average size of 48.6 nm. The electrochemical sensor (AgNPs/CPE) was fabricated by dipping a carbon paste electrode (CPE) in the AgNPs colloidal solution. The sensor shows acceptable linearity with ODZ concentration in the linear range from 1.0 × 10−5 to 1.0 × 10−3 M with a limit of detection (LOD =3S/P) and quantification (LOQ =10S/P) of 7.58 × 10−7 M and 2.08 × 10−6 M respectively.
•Extraction of cellulose from Phoenix dactylifera seed and their characterization.•Utilization of the extracted cellulose in the synthesis of silver nanoparticles (AgNPs).•Preparation of new sensor based on synthesized AgNPs, to evaluate the electrocatalytic behavior of ODZ.•Electrochemical detection of ODZ in commercial milk and water samples using the proposed method.
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