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.
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.
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.
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•The hetero-structured of Nd-doped g-C3N4/BiOI was prepared by a two-step process.•Nd doping and heterojunction between g-C3N4 and BiOI greatly affected PEC properties.•Improved ...photocurrent density was observed due to the increased light absorption.•The optimal catalyst gave superior hydrogen evolution rate of 288 μmol h−1 cm−2.•Enhanced charge separation efficiency and reduced charge recombination was obtained.
A two-step thermal poly-condensation and hydrothermal method is used to prepare noble metal-free nano-heterostructure of neodymium (Nd)-doped graphitic carbon nitride (g-C3N4) and bismuth oxyiodide (BiOI). The synthesised Nd- doped g-C3N4/BiOI heterostructure shows high electron-hole separation. Moreover, a fast charge transport at the heterojunction is noted and further leads to low charge recombination rate. Consequently, the synthesised heterostructure overcomes the high charge recombination rate of g-C3N4. This work reports the effect of Nd- doping and the formed heterojunction on the structural, optical, electrical conductivity and photoelectrochemical (PEC) properties of the heterostructure. Moreover, introducing Nd dopant into g-C3N4 enhances visible light absorption of g-C3N4. The optimal hetero-nanostructure (5.0 wt% Nd doped g-C3N4/BiOI) shows high photocurrent density (15.50 mA/cm2) and hydrogen evolution rate (288 μmol h−1 cm−2) under visible light (λ ≥ 420 nm) illumination when compared to other wt.% of Nd doped g-C3N4 and heterostructure. Additionally, the low emission features obtained from the photoluminescence studies and the heterojunction visually observed by HRTEM strongly emphasise that the formation of heterostructure leads to low recombination of charge carriers. Doping and forming heterostructure is shown to be an effective, controllable and an optimal approach to improve the PEC water splitting performance of g-C3N4.
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.
Abstract
Humidity sensing has been offering a noticeable contribution in different industrial, medical, and agricultural activities. Here, graphene quantum dots doped with polyaniline (PANI) and MnO
...2
were successfully prepared. The synthesized system is exposed to a set of structural, morphological, and optical investigations. The apparent crystallite size is less than 30 nm, reflecting the nanoscale of the structure, and thus validating the preparation route as evident on XRD pattern. SEM images show a fibrous structure where polyaniline dominates and covers most of the structure’s surface. The evident bands of the FTIR spectrum are designated to the component used in synthesis confirming the chemical structure of the fabricated system. The humidity sensing study of the synthesized structure is carried out through a wide range of relative humidity (RH) levels range of 11–97%. The response and recovery times of the fabricated structure are found to be around 120 and 220s, respectively.
Cancer is the most frequent life-threatening disease which has the highest mortality rate throughout the world. Diagnosis of cancer at the early stage can plays a critical role for its effective and ...successful treatment. Traditional diagnostic methods for cancer screening are costly, time-consuming, and not practical for repeated screenings. However, a biomarker-based cancer diagnosis is emerging as one of the most promising strategies for early diagnosis, monitoring disease progression, and subsequent cancer treatment. This review describes the recent advances and improvements in the electrochemical biosensors designed for detecting various cancer biomarkers using different signal transduction techniques and biological recognition strategies.
•Electrochemical biosensor helps to early diagnosis of cancer biomarkers.•Different electrochemical transduction system strategies are well explained.•More than 75 recent research articles on biosensors for cancer biomarker detection have been reviewed.•The advantages and future perspectives of each biosensor are highlighted.
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.
Conventional systems for drug delivery vehicles face many limitations, thus, there have been an extensive investigation for alternative strategies. In the last decade, nanotechnology had shown a ...great potential for the use in biomedical and pharmaceutical fields such as targeted drug delivery systems (DDS). Furthermore, nanotechnology had a gradually improving effect in preclinical advancing research, thus defining the evolving scientific field of nanomedicine. The use of targeted DDS can enhance the transport and local concentration of drugs. Owing to their small size and high drug loading and release efficiencies, nanoparticles (NPs) and nanostructured materials have been greatly considered a potential candidate for transporting drugs to the targeted site of action. Furthermore, Nanocarriers with conjugated drugs can enhance the biological delivery of drugs and improve their circulation in blood stream. Among the numerous different kinds of nanomaterials that have been investigated and reported, those based on metal oxide nanoparticles have attracted the interest of researchers due to their attractive properties such as simple surface functionalization, porosity, high stability, tunable shape and easy preparation processes. Metal oxide nanoparticles have been investigated for various biomedical applications such as medical imaging, drug delivery, gene therapy, hyperthermia related therapies, antioxidant treatment, photodynamic therapy, dentistry, and wound healing strategies. This work goals to review the main aspects regarding Metal oxide nanoparticles, highlighting the main biomedical and pharmaceutical applications of iron oxide, titanium dioxide, zinc oxide and copper oxides mainly focusing on their applications in targeted drug delivery towards the treatment of global infectious diseases and cancer.
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Correction for 'Development of electrochemical sensors for quick detection of environmental (soil and water) NPK ions' by M. I. Hossain
et al.
,
RSC Adv.
, 2024,
14
, 9137-9158,
...https://doi.org/10.1039/D4RA00034J
.
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