In recent years, there has been a rapid increase in demand for wearable sensors, particularly these tracking the surroundings, fitness, and health of people. Thus, selective detection in human body ...fluid is a demand for a smart lifestyle by quick monitoring of electrolytes, drugs, toxins, metabolites and biomolecules, proteins, and the immune system. In this review, these parameters along with the main features of the latest and mostly cited research work on nanostructured wearable electrochemical and biosensors are surveyed. This study aims to help researchers and engineers choose the most suitable selective and sensitive sensor. Wearable sensors have broad and effective sensing platforms, such as contact lenses, Google Glass, skin-patch, mouth gourds, smartwatches, underwear, wristbands, and others. For increasing sensor reliability, additional advancements in electrochemical and biosensor precision, stability in uncontrolled environments, and reproducible sample conveyance are necessary. In addition, the optimistic future of wearable electrochemical sensors in fields, such as remote and customized healthcare and well-being is discussed. Overall, wearable electrochemical and biosensing technologies hold great promise for improving personal healthcare and monitoring performance with the potential to have a significant impact on daily lives. These technologies enable real-time body sensing and the communication of comprehensive physiological information.
In recent years, there has been a rapid increase in demand for wearable sensors, particularly these tracking the surroundings, fitness, and health of people.
Here we introduce a composite material that consists of graphene oxide (GO) sheets crosslinked with
-hydroxysuccinimide (NHS) and functionalized with gold nanoflowers (AuNFs). Furthermore, a screen ...printed electrode (SPE) modified with the introduced composite is electrochemically reduced to obtain an SPE/rGO-NHS-AuNFs electrode for sensitive and selective determination of chloramphenicol (CAP) antibiotic drug. The morphological structure of the as-prepared nanocomposite was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, cyclic voltammetry, Fourier-transform infrared spectroscopy and electrochemical impedance spectroscopy. The proposed sensor demonstrated excellent performance with a linear concentration range of 0.05 to 100 μM and a detection limit of 1 nM. The proposed electrode offers a high level of selectivity, stability, reproducibility and a satisfactory recovery rate for electrochemical detection of CAP in real samples such as blood serum, poultry feed, milk, eggs, honey and powdered milk samples. This further demonstrates the practical feasibility of the proposed sensor in food analysis.
An effective tool for early-stage selective detection of the foodborne bacterial pathogen Shigella flexneri (S. flexneri) is essential for diagnosing infectious diseases and controlling outbreaks. ...Here, a label-free electrochemical DNA biosensor for monitoring S. flexneri is developed. To fabricate the biosensor, detection probe (capture probe) is immobilized on the surface of poly melamine (P-Mel) and poly glutamic acid (PGA), and disuccinimidyl suberate (DSS) functionalized flexible indium tin oxide (ITO) electrode. Anthraquinone-2-sulfonic acid monohydrate sodium salt (AQMS) is used as a signal indicator for the detection of S. flexneri. The proposed DNA biosensor exhibits a wide dynamic range with concentration of the targets ranging from 1 × 10
to 1 × 10
molL
with a limit of detection (LOD) of 7.4 × 10
molL
in the complementary linear target of S. flexneri, and a detection range of 8 × 10
-80 cells/ml with a LOD of 10 cells/ml in real S. flexneri sample. The proposed flexible biosensor provides high specificity for the detection of S. flexneri compared to other target signals such as discrete base mismatches and different bacterial species. The developed biosensor displayed excellent recoveries in detecting S. flexneri in spiked food samples. Therefore, the proposed biosensor can serve as a model methodology for the detection of other pathogens in a broad span of industries.
All over the world, technology is becoming more and more prevalent in agriculture. Different types of instruments are already being used in this sector. For the time being, every farmer is trying to ...produce more crops on a piece of land. Eventually, soil loses its nutrients; however, to grow more crops, farmers use more fertilizers without knowing the proper conditions of the soil in real time. To overcome this issue, many scientists have recently focused on developing electrochemical sensors to detect macronutrients,
i.e.
, nitrogen (N), phosphorus (P), and potassium (K), in soil or water rapidly. In this review, we focus mainly on the recent developments in electrochemical sensors used for the detection of nutrients (NPK) in different types of samples. As it is outlined, the use of smart and portable electrochemical sensors can be helpful for the reduction of excess fertilizer and can play a vital role in maintaining suitable conditions in soils and water. We are optimistic that this review can guide researchers in the development of a portable and suitable NPK detection system for soil nutrients.
When a plant shows deficiency syndromes, sometimes it becomes too late for the farmer to apply fertilizer, as most rely on checking plant leaves to assess their nutrition level. Electrochemical sensors can bring revolution here. Other pollutants (NPK) can also be determined using these sensors.
In December 2019, an outbreak of coronavirus disease 2019 (COVID-19) commenced in Wuhan, China and affected around 210 countries and territories in a matter of weeks. It has a phylogenetic similarity ...to SARS-CoV and it was named coronavirus 2 (SARS-CoV-2) and caused severe acute respiratory syndrome that could lead to death. One of the promising therapeutic strategies for virus infection is the search for enzyme inhibitors among natural compounds using molecular docking in order to obtain products with minimal side effects. COVID-19 virus main protease plays a vital role in mediating viral transcription and replication, introducing it as an attractive antiviral agent target. Metabolic profiling of the aqueous extract of
L. (Salvadoraceae) aerial parts dereplicated eleven known flavonol glycosides using LC-HRESIMS. All the annotated flavonoids exhibited significant binding stability at the N3 binding site to different degrees, except isorhamnetin-3-
-β-d-glucopyranoside, when compared with the currently used COVID-19 main protease inhibitor, darunavir. Structural similarity between the identified flavonoids enabled the study of the relationship between their structure and interactions with the receptor in the N3 binding site of the COVID-19 main protease. The results indicate that the basic flavonol nucleus possesses activity itself. Moreover, the presence of a rutinose moiety at the 3 position of ring C and absence of an
-methyl group in ring B of the flavonol structure could increase the binding stability. This study provides a scientific basis for the health benefits of the regular use of
as it leaches bioactive flavonoids in the aqueous saliva.
This paper introduces an experimental study for concentrating solar cell performance cooled by using flat heat pipe. The cell represents the heat pipe evaporator, and the heat pipe condenser is ...cooled by using a rectangular finned heat sink. This study is investigated at various heat pipe condenser and adiabatic regions lengths and concentration ratios of the radiation intensity incident on the cell, and for forced and free convection airflow cooling through the finned heat sink. The required radiation energy supplied to the cell is provided by solar simulator. The findings illustrate that cell efficiency and output power increase with increasing the heat pipe condenser and decrease its adiabatic regions’ lengths. However, cell efficiency reduces with rising the incident radiation intensity. The heat pipe temperature increases with radiation intensity, but its maximum temperature difference does not change greatly with variation solar intensity. Cooling the cell by heat pipe increases its output power by 24.3% compared to free convection without utilizing heat pipe at incident energy 500 W m
−2
. Using forced convection with double condenser length increases the cell output power by about 9.1% compared to one heat sink for free convection at falling radiation intensity 3000 W m
−2
.
Abstract
The time-fractional derivative based on the Grunwald–Letnikove derivative of the 2D-ISPH method is applying to emulate the dual rotation on MHD natural convection in a hexagonal-shaped ...cavity suspended by nano-encapsulated phase change material (NEPCM). The dual rotation is performed between the inner fin and outer hexagonal-shaped cavity. The impacts of a fractional time derivative
$$\alpha$$
α
$$\left( {0.92 \le \alpha \le 1} \right)$$
0.92
≤
α
≤
1
, Hartmann number Ha
$$\left( {0 \le Ha \le 80} \right)$$
0
≤
H
a
≤
80
, fin length
$$\left( {0.2 \le L_{Fin} \le 1} \right)$$
0.2
≤
L
Fin
≤
1
, Darcy parameter Da
$$\left( {10^{ - 2} \le Da \le 10^{ - 4} } \right)$$
10
-
2
≤
D
a
≤
10
-
4
, Rayleigh number Ra
$$\left( {10^{3} \le Ra \le 10^{6} } \right)$$
10
3
≤
R
a
≤
10
6
, fusion temperature
$$\theta_{f}$$
θ
f
$$\left( {0.05 \le \theta_{f} \le 0.8} \right)$$
0.05
≤
θ
f
≤
0.8
, and solid volume fraction
$$\varphi$$
φ
$$\left( {0 \le \varphi \le 0.06} \right)$$
0
≤
φ
≤
0.06
on the velocity field, isotherms, and mean Nusselt number
$$\overline{Nu}$$
Nu
¯
are discussed. The outcomes signaled that a dual rotation of the inner fin and outer domain is affected by a time-fractional derivative. The inserted cool fin is functioning efficiently in the cooling process and adjusting the phase change zone within a hexagonal-shaped cavity. An increment in fin length augments the cooling process and changes the location of a phase change zone. A fusion temperature
$$\theta_{f}$$
θ
f
adjusts the strength and position of a phase change zone. The highest values of
$$\overline{Nu}$$
Nu
¯
are obtained when
$$\alpha = 1$$
α
=
1
. An expansion in Hartmann number
$$Ha $$
Ha
reduces the values of
$$\overline{Nu}$$
Nu
¯
. Adding more concentration of nanoparticles is improving the values of
$$\overline{Nu}$$
Nu
¯
.
An electrochemical sensor based on molecular imprinted polymer (MIP) to detect ceftizoxime (CFX) with high sensitivity and selectivity is demonstrated. MIP was synthesized by electropolymerization of ...poly-cysteine (P-Cys) on a multi-walled carbon nanotube (MWCNT) modified glassy carbon electrode (GCE). A targeted drug was used as a template molecule during the polymerization process. The bare GCE was coated with a layer of MWCNT before the synthesis of MIP to improve the sensor sensitivity. Experimental parameters such as polymerization conditions, the influence of pH, molar ratio of the template molecules and the monomer molecules were all optimized. The peak potential exhibited linearity with CFX concentration in the ranges of 1
×
10
-
9
–1×
10
-
7
molL
−1
(
R
2
= 0.9904) and 2×
10
-
7
–1×
10
-
4
molL
−1
(
R
2
= 0.9949). The LOD of the MIP sensor was found to be
1
×
10
-
10
molL
−1
under optimal conditions using a differential pulse voltammetry (DPV). The proposed sensor was tested on real samples, and good recovery results were obtained.
Purpose
This paper aims to adopt incompressible smoothed particle hydrodynamics (ISPH) method to simulate MHD double-diffusive natural convection in a cavity containing an oscillating pipe and filled ...with nanofluid.
Design/methodology/approach
The Lagrangian description of the governing partial differential equations are solved numerically using improved ISPH method. The inner oscillating pipe is divided into two different pipes as an open and a closed pipe. The sidewalls of the cavity are cooled with a lower concentration C_c and the horizontal walls are adiabatic. The inner pipe is heated with higher concentration C_h. The analysis has been conducted for the two different cases of inner oscillating pipes under the effects of wide range of governing parameters.
Findings
It is found that a suitable oscillating pipe makes a well convective transport inside a cavity. Presence of the oscillating pipe has effects on the heat and mass transfer and fluid intensity inside a cavity. Hartman parameter suppresses the velocity and weakens the maximum values of the stream function. An increase on Hartman, Lewis and solid volume fraction parameters leads to an increase on average Nusselt number on an oscillating pipe and left cavity wall. Average Sherwood number on an oscillating pipe and left cavity wall decreases as Hartman parameter increases.
Originality/value
The main objective of this work is to study the MHD double-diffusive natural convection of a nanofluid in a square cavity containing an oscillating pipe using improved ISPH method.
Even though the ad-hoc on-demand distance vector (AODV) is a broadly used routing protocol for mobile ad-hoc networks (MANETs), it is vulnerable to a blackhole attack. Lu et al. developed a secure ...MANET routing protocol called SAODV to address the security weakness associated with the original AODV protocol and to remedy the blackhole attack. Specifically, the SAODV protocol can protect against blackhole attack performed by a malicious node during the routing process. However, it cannot resist the cooperative blackhole attack, in which two nodes are participating together to mount such attack. Therefore, this paper proposes a secure MANET routing protocol called BP-AODV to overcome the security breaches related to the SAODV protocol along with the original AODV protocol. In addition, the BP-AODV is able to protect against a cooperative blackhole attack launched during the routing process and guards against the blackhole attack that might take place during the forwarding process. The BP-AODV is developed by extending the functionality of the AODV protocol along with utilizing the chaotic map features. The experimental results assure that the BP-AODV protocol is more secure than the SAODV protocol and can effectively fight the blackhole attack achieved by a malicious node or cooperative malicious nodes during the routing process. The results also reveal that the BP-AODV can strongly guard against the blackhole attack that occurs during the forwarding process.
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