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1 – 10 of 298O.O. Adejumo and J.O. Ojo
The results of trial experiments carried out with a computer simulation model of total reflection X‐ray fluorescence, TXRF system to determine optimum conditions for detecting…
Abstract
The results of trial experiments carried out with a computer simulation model of total reflection X‐ray fluorescence, TXRF system to determine optimum conditions for detecting certain elements of interest under various analytical conditions in a given ten‐element standard sample is presented in this paper. Results of these trial experiments show that the detectability of elements improved with increasing applied voltages up to about 43kV (for a Molybdenum anode TXRF spectrometer) and atomic number of elements. Variation of geometry such as the glancing incidence angle of the excitation beam reflected slight increase in minimum detection limit, MDL values as the angle of incidence is reduced from an optimum value of 1.6mradian to 1.0mradian. The nature of the sample support was observed to affect the detectability of the elements as good detection limits were obtained if gold is used as sample holder..
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Mulayam Singh Gaur, Rajni Yadav, Mamta Kushwah and Anna Nikolaevna Berlina
This information will be useful in the selection of materials and technology for the detection and removal of mercury ions at a low cost and with high sensitivity and selectivity…
Abstract
Purpose
This information will be useful in the selection of materials and technology for the detection and removal of mercury ions at a low cost and with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity.
Design/methodology/approach
Different nano- and bio-materials allowed for the development of a variety of biosensors – colorimetric, chemiluminescent, electrochemical, whole-cell and aptasensors – are described. The materials used for their development also make it possible to use them in removing heavy metals, which are toxic contaminants, from environmental water samples.
Findings
This review focuses on different technologies, tools and materials for mercury (heavy metals) detection and remediation to environmental samples.
Originality/value
This review gives up-to-date and systemic information on modern nanotechnology methods for heavy metal detection. Different recognition molecules and nanomaterials have been discussed for remediation to water samples. The present review may provide valuable information to researchers regarding novel mercury ions detection sensors and encourage them for further research/development.
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Xingxing Li, Shixi You, Zengchang Fan, Guangjun Li and Li Fu
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health…
Abstract
Purpose
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health care. The purpose of this paper is to summarize the current state of the field, identify challenges and limitations and discuss future prospects for the development of saliva-based electrochemical sensors.
Design/methodology/approach
The paper reviews relevant literature and research articles to examine the latest developments in electrochemical sensing technologies for saliva analysis. It explores the use of various electrode materials, including carbon nanomaterial, metal nanoparticles and conducting polymers, as well as the integration of microfluidics, lab-on-a-chip (LOC) devices and wearable/implantable technologies. The design and fabrication methodologies used in these sensors are discussed, along with sample preparation techniques and biorecognition elements for enhancing sensor performance.
Findings
Electrochemical sensors for salivary analyte detection have demonstrated excellent potential for noninvasive, rapid and cost-effective diagnostics. Recent advancements have resulted in improved sensor selectivity, stability, sensitivity and compatibility with complex saliva samples. Integration with microfluidics and LOC technologies has shown promise in enhancing sensor efficiency and accuracy. In addition, wearable and implantable sensors enable continuous, real-time monitoring of salivary analytes, opening new avenues for personalized health care and disease management.
Originality/value
This review presents an up-to-date overview of electrochemical sensors for analyte detection in saliva, offering insights into their design, fabrication and performance. It highlights the originality and value of integrating electrochemical sensing with microfluidics, wearable/implantable technologies and point-of-care testing platforms. The review also identifies challenges and limitations, such as interference from other saliva components and the need for improved stability and reproducibility. Future prospects include the development of novel microfluidic devices, advanced materials and user-friendly diagnostic devices to unlock the full potential of saliva-based electrochemical sensing in clinical practice.
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Xinran Yang, Junhui Du, Hongshuo Chen, Chuanjin Cui, Haibin Liu and Xuechao Zhang
Field-effect transistor (FET) has excellent electronic properties and inherent signal amplification, and with the development of nanomaterials technology, FET biosensors with…
Abstract
Purpose
Field-effect transistor (FET) has excellent electronic properties and inherent signal amplification, and with the development of nanomaterials technology, FET biosensors with nanomaterials as channels play an important role in the field of heavy metal ion detection. This paper aims to review the research progress of silicon nanowire, graphene and carbon nanotube field-effect tube biosensors for heavy metal ion detection, so as to provide technical support and practical experience for the application and promotion of FET.
Design/methodology/approach
The article introduces the structure and principle of three kinds of FET with three kinds of nanomaterials, namely, silicon nanowires, graphene and carbon nanotubes, as the channels, and lists examples of the detection of common heavy metal ions by the three kinds of FET sensors in recent years. The article focuses on the advantages and disadvantages of the three sensors, puts forward measures to improve the performance of the FET and looks forward to its future development direction.
Findings
Compared with conventional instrumental analytical methods, FETs prepared using nanomaterials as channels have the advantages of fast response speed, high sensitivity and good selectivity, among which the diversified processing methods of graphene, the multi-heavy metal ions detection of silicon nanowires and the very low detection limit and wider detection range of carbon nanotubes have made them one of the most promising detection tools in the field of heavy metal ions detection. Of course, through in-depth analysis, this type of sensor has certain limitations, such as high cost and strict process requirements, which are yet to be solved.
Originality/value
This paper elaborates on the detection principle and classification of field-effect tube, investigates and researches the application status of three kinds of FET biosensors in the detection of common heavy metal ions. By comparing the advantages and disadvantages of each of the three sensors in practical applications, the paper focuses on the feasibility of improvement measures, looks forward to the development trend in the field of heavy metal detection and ultimately promotes the application of field-effect tube development technology to continue to progress, so that its performance continues to improve and the application field is constantly expanding.
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Yap Wing Fen and W. Mahmood Mat Yunus
The purpose of this paper is to review the novel application of surface plasmon resonance (SPR) in sensing heavy metal ions and the development of SPR to become an alternative…
Abstract
Purpose
The purpose of this paper is to review the novel application of surface plasmon resonance (SPR) in sensing heavy metal ions and the development of SPR to become an alternative heavy metal ions sensor.
Design/methodology/approach
The possible dangerous toxic effects of heavy metal ions are revealed in the short introduction. The existing conventional methods for sensing heavy metal ions and their drawbacks are also discussed. To overcome these drawbacks, SPR has been investigated from the basic principle to the potential alternative in sensing heavy metal ions.
Findings
Application of SPR in sensing heavy metal ions emerged a decade ago. A wide range of active layers or recognition elements (e.g. polymer, protein, nanoparticles) have been developed to combine with SPR. The detection limit, sensitivity and selectivity of SPR sensing in heavy metal ions have been improved from time to time, until the present.
Originality/value
This paper provides up-to-date and systematic information on SPR sensing for heavy metal ions. Different advancements on active layers or recognition molecules have been discussed in detail and arranged in the order of their chronological evolution. The present review may provide researchers with valuable information regarding novel heavy metal ions sensor using SPR and encourage them to take this area for further research and development.
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Amit Kumar Sharma, M.S. Gaur, Pradeep Sharma, R.K. Tiwari and Seema Bhadoria
The purpose of this paper is to develop a sensitive and cost effective colorimetric sensor for detection of methyl parathion (MP) using simple circuitry. A simple and sensitive…
Abstract
Purpose
The purpose of this paper is to develop a sensitive and cost effective colorimetric sensor for detection of methyl parathion (MP) using simple circuitry. A simple and sensitive concept of colorimetric sensor instrument represents a rapidly expanding field of sensor techniques to monitor MP neurotoxins is described within certain conditions of producing color in samples. The variation of intensity of color with concentration provides discrimination between different concentrations of MP. The colorimetric instrument displays well‐defined signals towards hydrolyzed samples of MP.
Design/methodology/approach
The principle of light intensity measurement has been applied to measure various concentrations of MP based on Lambert‐Beer theory. This device and its processes are useful for quantitative analysis of MP. The detection limits were found within a range of 0.1‐1.5 ppm.
Findings
The experiments from sophisticated analytical techniques are costly and time‐consuming processes that validate the proposed system.
Practical implications
This paper's original proposition of using quantification of MP with colorimetric sensor instrument obtained promising results.
Originality/value
The colorimetric sensor instrument provides a new method for quantification of MP in unknown samples within detection limits.
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Xingya Wang and Guangchang Pang
This paper aims to provide a detailed review of weak interaction biosensors and several common biosensor methods for magnifying signals, as well as judiciously guide readers…
Abstract
Purpose
This paper aims to provide a detailed review of weak interaction biosensors and several common biosensor methods for magnifying signals, as well as judiciously guide readers through selecting an appropriate detecting system and signal amplification method according to their research and application purpose.
Design/methodology/approach
This paper classifies the weak interactions between biomolecules, summarizes the common signal amplification methods used in biosensor design and compares the performance of different kinds of biosensors. It highlights a potential electrochemical signal amplification method: the G protein signaling cascade amplification system.
Findings
Developed biosensors which, based on various principles, have their own strengths and weaknesses have met the basic detection requirements for weak interaction between biomolecules: the selectivity, sensitivity and detection limit of biosensors have been consistently improving with the use of new signal amplification methods. However, most of the weak interaction biosensors stop at the research stage; there are only a minority realization of final commercial application.
Originality/value
This paper evaluates the status of research and application of weak interaction biosensors systematically. The G protein signaling cascade amplification system proposal offers a new avenue for the research and development of electrochemical biosensors.
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Munir H. Shah, M. Jaffar, N. Shaheen and N. Rasool
This paper seeks to apply an improved electrometric method using polarized electrodes to quantify iodine in 241 salt samples pertaining to 15 different brands procured from the…
Abstract
Purpose
This paper seeks to apply an improved electrometric method using polarized electrodes to quantify iodine in 241 salt samples pertaining to 15 different brands procured from the local market.Design/methodology/approach – Comparative evaluation of the method is made with the iodometric titration and the colorimetric methods.
Findings
The results obtained reveal that the electrometric method excels in attaining higher level of accuracy, precision and lower detection limit, backed by ease of operation.
Practical implications
The method warrants reproducible results both for replicate synthetic and market samples, with a lower detection limit of about 0.1ppm within an acceptable limit of error.
Originality/value
The study shows significant difference between the estimated and labelled iodine values in various brands of iodized salts. Most of the salt samples analysed contain iodine levels far exceeding the WHO permitted limit. The method has the potential of application for in‐situ iodine measurement in iodine fortified salts to ensure rapid quality control, both at the retailer and production levels.
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Ilhem Ghodbane, Rochdi Kherrrat, Saida Zougar, Rim Lamari, Redouane Haddadji and Mohamed Saleh Medjram
The purpose of this work is to explore electrical properties of an electrochemical sensor designed for the detection of malachite green (MG) present in an aqueous solution.
Abstract
Purpose
The purpose of this work is to explore electrical properties of an electrochemical sensor designed for the detection of malachite green (MG) present in an aqueous solution.
Design/methodology/approach
The present sensor consists in the spatial coupling of a polymeric membrane and an ion-sensitive electrode (platinum electrode). The preparation of the polymeric membrane involves the incorporation of an ionophore (D2HPA), a polymer (polyvinylchloride [PVC]) and a plasticizer (dioctyl phthalate [DOP]). Several techniques have been used to characterize this sensor: the cyclic voltammetry, the electrochemical impedance spectroscopy and the optical microscopy. The sensibility, the selectivity and the kinetic study of a modified platinum electrode have been evaluated by cyclic voltammetry.
Findings
The obtained results reveal the possibility of a linear relationship between the current of reduction peaks and MG concentration. A linear response was obtained in a wide-concentration range that stretches from 10−5 to 10−13 mol L−1, with a good correlation coefficient (0.976) and a good detection limit of 5.74 × 10−14 mol L−1 (a signal-to-noise ratio of 3). In addition, the voltammetric response of modified electrode can be enhanced by adding a layer of Nafion membrane. Under this optimal condition, a linear relationship was obtained, with a correlation coefficient of 0.986 and a detection limit of 1.92 × 10−18 mol L−1.
Originality/value
In the present research, a convenient, inexpensive and reproducible method for the detection of MG was developed. The developed sensor is capable of competing against the conventional techniques in terms of speed, stability and economy.
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Faisal K. Algethami, Hadi M. Marwani, Abdullah M. Asiri and Mohammed M. Rahman
The purpose of this study is to prepare various CeO2-based carbon material (CNT, CB, GO) nanocomposites through a wet chemical process for the development of a sensor probe to…
Abstract
Purpose
The purpose of this study is to prepare various CeO2-based carbon material (CNT, CB, GO) nanocomposites through a wet chemical process for the development of a sensor probe to detect various environmental toxins by using an electrochemical approach under room temperature conditions. A comparative study on sensitive and selective phenolic sensor (4-methoxyphenol; 4-MP) has been fabricated by modifying a glassy carbon electrode (GCE) with various nanocomposites (NCs) such as CeO2, CeO2–CNT (carbon nanotubes), CeO2–CB (carbon black) and CeO2–GO (graphene oxide) NCs.
Design/methodology/approach
The CeO2–CNT NCs were prepared by the wet chemical method at low temperature. NCs were characterized by various methods such as transmission electron microscopy (TEM), Fourier-transform infra-red (FTIR), ultra-violet/visible (UV-Vis) spectroscopy and XRD (X-ray diffraction). CeO2–CNT NCs were immobilized as a film on the flat surface of the GCE by using binders (5% Nafion). The electrochemical measurements of the 4-MP detection with the CeO2–CNT NCs/Nafion/GCE sensor were studied by the current-voltage method.
Findings
In the optimal conditions, the sensitivity, detection limit and limit of quantification of 4-MP sensor probe were found to be 47.56 µAcm-2 µM−1, 12.0 ± 0.2 nM and 40.0 ± 0.5 nM (S/N of 3), respectively.
Research limitations/implications
This electrochemical sensor showed an acceptable analytical performance in the detection of 4-MP with higher sensitivity, lower detection limit, large dynamic concentration range, good reproducibility and fast response time.
Practical implications
This electrochemical approach can be applied practically for the determination of selective 4-MP in real environmental and extracted samples.
Social implications
CeO2–CNT NCs/Nafion/GCE sensor probe was used for the safety of environmental and health-care fields at larger scales.
Originality/value
This electrochemical approach is a significant achievement on the development of sensor probe. The results are indicated as being technically detailed with an up-to-date account of recent chemical sensor research studies.
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