Antibiotics are extensively employed as bacteriostatic agents for fighting against microbial infection in animals. However, inappropriate doses of antibiotic drugs may result in antibiotic residues ...in food of animal origin and may cause various side effects on human health. Moreover, the transferor of antibiotic-resistant bacteria to humans through the food chain may induce serious health hazards. Hence, it is vital to develop sensitive and selective methods for rapid screening and regular monitoring of antibiotic residues in animal-derived foods. The conventional different chromatographic and spectroscopic techniques are time-consuming, expensive and require skilled personnel. To overcome such limitations, biosensors have emerged as an innovative approach recently and integrated with nanotechnologies for sensitive, rapid and on-site monitoring of different antibiotic residues in animal origin foods. This mini-review aims to give an overview of the currently available biosensing techniques to detect antibiotic residue in foods.
The authors introduced waste plastic pyrolysis oil (WPPO) as an alternative fuel characterized in detail and compared with conventional diesel. High density polyethylene, HDPE, was pyrolyzed in a ...self-designed stainless steel laboratory reactor to produce useful fuel products. HDPE waste was completely pyrolyzed at 330–490°C for 2-3 hours to obtain solid residue, liquid fuel oil, and flammable gaseous hydrocarbon products. Comparison of the fuel properties to the petrodiesel fuel standards ASTM D 975 and EN 590 revealed that the synthetic product was within all specifications. Notably, the fuel properties included a kinematic viscosity (40°C) of 1.98 cSt, density of 0.75 gm/cc, sulphur content of 0.25 (wt%), and carbon residue of 0.5 (wt%), and high calorific value represented significant enhancements over those of conventional petroleum diesel fuel.
An innovative biosensor assembly relying on glassy carbon electrodes modified with nanocomposites consisting of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as a host matrix ...with functionalized gold nanoparticles (GCE/PEDOT:PSS-AuNPs) is presented for the selective and sensitive detection of xanthine (XA). The developed sensor was successfully applied for the quantification of XA in the presence of significant interferents like hypoxanthine (HXA) and uric acid (UA). Different spectroscopy and electron microscopy analyses were done to characterize the as-prepared nanocomposite. Calibration responses for the quantification of XA was linear from 5.0 × 10
−8
to 1.0 × 10
−5
M (
R
2
= 0.994), with a detection limit as low as 3.0 × 10
−8
(S/N = 3). Finally, the proposed sensor was applied for the analyses of XA content in commercial fish and meat samples and satisfactory recovery percentage was obtained.
An innovative biosensor with glassy carbon electrodes modified with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate nanocomposites as a host matrix with functionalized gold nanoparticles for the selective and sensitive detection of xanthine.
Last few decades, viruses are a real menace to human safety. Therefore, the rapid identification of viruses should be one of the best ways to prevent an outbreak and important implications for ...medical healthcare. The recent outbreak of coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus which belongs to the single-stranded, positive-strand RNA viruses. The pandemic dimension spread of COVID-19 poses a severe threat to the health and lives of seven billion people worldwide. There is a growing urgency worldwide to establish a point-of-care device for the rapid detection of COVID-19 to prevent subsequent secondary spread. Therefore, the need for sensitive, selective, and rapid diagnostic devices plays a vital role in selecting appropriate treatments and to prevent the epidemics. During the last decade, electrochemical biosensors have emerged as reliable analytical devices and represent a new promising tool for the detection of different pathogenic viruses. This review summarizes the state of the art of different virus detection with currently available electrochemical detection methods. Moreover, this review discusses different fabrication techniques, detection principles, and applications of various virus biosensors. Future research also looks at the use of electrochemical biosensors regarding a potential detection kit for the rapid identification of the COVID-19.
•Electrochemical biosensing platform helps to early diagnosis of pathogenic viruses.•Different electrochemical transduction system strategies are explained.•We covered more than 125 recent research articles on virus biosensors.•The advantages of each biosensor for COVID-19 detection are highlighted.•The advantages, drawbacks, and future perspectives of biosensors are discussed.
The concentrations of major (Si, Al, Ca, Fe, and K) and minor (Cd, Mn, Ni, Pb, U, Zn, Co, Cr, As, Cu, Rb, Sr, and Zr,) elements in the surficial sediments were studied in an attempt to establish ...their concentration in the Bengal coast. It was revealed that the majority of the trace elements have been introduced into the Bengal marine from the riverine inflows that are also affected by the impact of industrial, ship breaking yard, gas production plant, and urban wastes. The concentration of heavy metals was measured using Atomic Absorption Spectroscopy and Energy Dispersive X-ray fluorescence instruments. The highest concentrations for several trace elements were thus recorded which generally decrease with distance from the coast. It was observed that the heavy metal concentrations in the sediments generally met the criteria of international marine sediment quality. However, both the contamination factor and pollution load index values suggested the elevation of some metals’ concentrations in the region. Constant monitoring of the Bengal coast water quality needs to be recorded with a view to minimizing the risk of health of the population and the detrimental impacts on the aquatic ecosystem.
The flow and heat transfer in a trapezoidal cavity were investigated numerically. Water-based ferrofluid with Fe3O4 nanoparticles and porous medium with low Darcy number were chosen for the ...investigation. Both side walls were maintained at a constant cold temperature, the top wall was adiabatic, and the heater is placed at the bottom wall. The dimensionless governing equations are solved numerically using finite element method. A uniform magnetic field of strength B0 was imposed. It is assumed that the magnetic Reynolds number is much smaller than the induced magnetic field so that it can be neglected when compared to the applied magnetic field. No slip boundary conditions were applied at the walls. The streamlines and isotherms were generated to explain the behaviour of dimensionless velocity and temperature inside the cavity. It is demonstrated that the magnetic field, thermal buoyancy, porous medium permeability and the length of the heating element play a crucial role in the enhancement of dimensionless average heat transfer rate.
Bacterial biofilm plays a pivotal role in bioremediation of heavy metals from wastewaters. In this study, we isolated and identified different biofilm producing bacteria from wastewaters. We also ...characterized the biofilm matrix i.e., extracellular polymeric substances (EPS) produced by different bacteria. Out of 40 isolates from different wastewaters, only 11 (27.5%) isolates (static condition at 28°C) and 9 (22.5%) isolates (agitate and static conditions at 28 and 37°C) produced air-liquid (AL) and solid-air-liquid (SAL) biofilms, respectively, only on salt-optimized broth plus 2% glycerol (SOBG) but not in other media tested. Biomass biofilms and bacteria coupled with AL biofilms were significantly (
≤ 0.001) varied in these isolates.
(isolate ENSD101 and ENST501),
(ENSD102),
(ENSH201),
(ENSH202 and ENSG304), uncultured
sp. (ENSG301 and ENSG305),
(ENSG302),
(ENSG303), and
(ENSW401) were identified based on 16S rRNA gene sequencing. Scanning electron microscope (SEM) images revealed that biofilm matrix produced by
ENSD102, uncultured
sp. ENSG301,
ENSG302, and
ENSG303 are highly fibrous, compact, and nicely interlinked as compared to the biofilm developed by
ENSH201 and
ENSW401. X-ray diffraction (XRD) results indicated that biofilm matrix produced by
ENSD102, uncultured
sp. ENSG301, and
ENSG302 are non-crystalline amorphous nature. Fourier transform infrared (FTIR) spectroscopy showed that proteins and polysaccharides are the main components of the biofilms. Congo red binding results suggested that all these bacteria produced proteinaceous curli fimbriae and cellulose-rich polysaccharide. Production of cellulose was also confirmed by Calcofluor binding- and spectrophotometric assays.
ENSD102,
sp. ENSG301, and
ENSG302 were tested for their abilities to form the biofilms exposure to 0 to 2000 mg/L of copper sulfate (for Cu), zinc sulfate (for Zn), lead nitrate (for Pb), nickel chloride (for Ni), and potassium dichromate (for Cr), several concentrations of these metals activated the biofilm formation. The polysaccharides is known to sequester the heavy metals thus, these bacteria might be applied to remove the heavy metals from wastewater.
In this experiment, a highly effective electrochemical sensor based on a molecularly imprinted polymer has been developed for ultrasensitive detection of dimetridazole. The sensor was made by ...incorporating of dimetridazole as a template molecule during the electropolymerization of poly-arginine on a glassy carbon electrode. The modified electrode GCE/P-Arg@MIP was characterized by voltammetric and microscopic techniques. Differential pulse voltammetry method was used to detect target analyte under the optimum condition. The DPV response to dimetridazole was linear at 0.1 × 10−9 to 10 × 10−6 mol L−1 (R2 = 0.996), with a method detection limit (S/N = 3) of 0.1 × 10−9 mol L−1. Moreover, the proposed sensor shows satisfactory recovery ranges for the determination dimetridazole in commercially available egg, milk and honey samples.
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•Highly effective electrochemical MIP sensor developed for ultrasensitive detection of dimetridazole.•GCE/P-Arg@MIP electrode was fabricated via electrochemical deposition technique.•The proposed sensor exhibited a wide linear detection range with an LOD of 0.1 nM.•The GCE/P-Arg@MIP sensor was applied to detect analyte in egg, milk and honey.
An innovative electrochemical sensor assembly relying on a simple “green” electrochemical reduction route is presented for the sensitive detection of 8-hydroxy-2′-deoxyguanosine (8-OHdG), the most ...abundant oxidative product of DNA. The sensing film consisted of poly (L-arginine) and graphene wrapped Au nanoparticles was fabricated on glassy carbon electrode (GCE/P-Arg/ErGO-AuNPs) using subsequent ‘layer-by-layer’ regime through electrochemical technique. The proposed method was also successfully applied for the quantification of 8-OHdG in the presence of interfering biomolecules like ascorbic acid and uric acid. Scanning electron microscopy (SEM) was utilized to characterize the surface morphology of the composite electrode. Electrochemical characterizations of the bare and modified electrodes were carried out via cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). According to differential pulse voltammetry (DPV) results, there were linear relationships between the peak currents and the concentrations in the ranges of 1.0–100 nM (R2 = 0.996), and 0.5–10 µM (R2 = 0.990), with a detection limit (S/N = 3) of 1.0 nM. Furthermore, the proposed sensor was successfully applied for the determination of target analyte in human urine samples and a very high recovery percentage was obtained.
•GCE/P-Arg/ErGO-AuNPs electrode was fabricated via ‘layer-by-layer’ electrochemical technique.•The modified electrode was prepared for determination of 8-OHdG.•The proposed sensor exhibited a wide linear detection range with an LOD of 1nM.•The GCE/P-Arg/ErGO-AuNPs sensor was applied to detect 8-OHdG in human urine sample.
Abstract
l
-Cysteine coated zinc oxide (ZnO) nano hollow spheres were prepared as a potent drug delivery agent to eradicate
Salmonella enterica
serovar Typhimurium (
S. typhimurium
). The ZnO nano ...hollow spheres were synthesized by following the environmentally-friendly trisodium citrate assisted method and
l
-cysteine (L-Cys) conjugate with its surface. ZnO/L-Cys@CFX nanocarrier drug has been fabricated by incorporating ceftizoxime with L-Cys coated ZnO nano hollow spheres and characterized using different techniques such as scanning electron microscope (SEM), attenuated total reflection Fourier transform infrared (ATR-FTIR), and X-ray diffraction (XRD) etc. Furthermore, the drug-loading and encapsulation efficiency at different pH levels was measured using UV–vis spectrometer and optimized. A control and gradual manner of pH-sensitive release profile was found after investigating the release profile of CFX from the carrier drug. The antibacterial activity of ZnO/L-Cys@CFX and CFX were evaluated through the agar disc diffusion method and the broth dilution method, which indicate the antibacterial properties of antibiotics enhance after conjugating. Surprisingly, the ZnO/L-Cys@CFX exhibits a minimum inhibitory concentration (MIC) of 5 µg/ml against
S. typhimurium
is lower than CFX (20 µg/ml) itself. These results indicate the nanocarrier can reduce the amount of CFX dosed to eradicate
S. typhimurium
.
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