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Mikrochimica Acta Nov 2022Electrode miniaturization has profoundly revolutionized the field of electrochemical sensing, opening up unprecedented opportunities for probing biological events with a... (Review)
Review
Electrode miniaturization has profoundly revolutionized the field of electrochemical sensing, opening up unprecedented opportunities for probing biological events with a high spatial and temporal resolution, integrating electrochemical systems with microfluidics, and designing arrays for multiplexed sensing. Several technological issues posed by the desire for downsizing have been addressed so far, leading to micrometric and nanometric sensing systems with different degrees of maturity. However, there is still an endless margin for researchers to improve current strategies and cope with demanding sensing fields, such as lab-on-a-chip devices and multi-array sensors, brain chemistry, and cell monitoring. In this review, we present current trends in the design of micro-/nano-electrochemical sensors and cutting-edge applications reported in the last 10 years. Micro- and nanosensors are divided into four categories depending on the transduction mechanism, e.g., amperometric, impedimetric, potentiometric, and transistor-based, to best guide the reader through the different detection strategies and highlight major advancements as well as still unaddressed demands in electrochemical sensing.
Topics: Electrodes; Microfluidics; Potentiometry; Lab-On-A-Chip Devices
PubMed: 36416992
DOI: 10.1007/s00604-022-05548-3 -
Biosensors Jan 2022The review describes fentanyl and its analogs as new synthetic opioids and the possibilities of their identification and determination using electrochemical methods... (Review)
Review
The review describes fentanyl and its analogs as new synthetic opioids and the possibilities of their identification and determination using electrochemical methods (e.g., voltammetry, potentiometry, electrochemiluminescence) and electrochemical methods combined with various separation methods. The review also covers the analysis of new synthetic opioids, their parent compounds, and corresponding metabolites in body fluids, such as urine, blood, serum, and plasma, necessary for a fast and accurate diagnosis of intoxication. Identifying and quantifying these addictive and illicit substances and their metabolites is necessary for clinical, toxicological, and forensic purposes. As a reaction to the growing number of new synthetic opioid intoxications and increasing fatalities observed over the past ten years, we provide thorough background for developing new biosensors, screen-printed electrodes, or other point-of-care devices.
Topics: Analgesics, Opioid; Fentanyl
PubMed: 35049654
DOI: 10.3390/bios12010026 -
Journal of Analytical Methods in... 2019The prescription of psychotropic drugs, especially benzodiazepines (BZDs), occupies a preponderant place in the management of mental illnesses. Indeed, the BZDs have... (Review)
Review
The prescription of psychotropic drugs, especially benzodiazepines (BZDs), occupies a preponderant place in the management of mental illnesses. Indeed, the BZDs have been used in different therapeutic areas including insomnia, anxiety, seizure disorders, or general anesthesia. Unfortunately, these drugs are present in the illegal street market, leading to a lot of drug abuse amongst some addicted users, road insecurity, and suicide. Hence, it has become essential to analyze the BZDs drugs in human biological specimens for drug abuse in forensic sciences. The present review provides a summary of sample preparation techniques (solid-phase extraction and Liquid-liquid phase extraction) and the methods for the detection and quantification of BZDs molecules in the commonly used biological specimens over the ten last years which may potentially lead to better and accurate evaluation of the physiological state of a given person. The commonly used methods for the detection and quantification of BZDs include nuclear magnetic resonance (NMR), chromatography (GC-MS, HPLC, and TLC), immunoassay (ELISA, RIA, LFA, CEDEA, FPIA, and KIMS), and electroanalytical methods (voltammetry and potentiometry).
PubMed: 31583157
DOI: 10.1155/2019/2035492 -
Molecules (Basel, Switzerland) May 2021Food safety and quality control pose serious issues to food industry and public health domains, in general, with direct effects on consumers. Any physical, chemical, or... (Review)
Review
Food safety and quality control pose serious issues to food industry and public health domains, in general, with direct effects on consumers. Any physical, chemical, or biological unexpected or unidentified food constituent may exhibit harmful effects on people and animals from mild to severe reactions. According to the World Health Organization (WHO), unsafe foodstuffs are especially dangerous for infants, young children, elderly, and chronic patients. It is imperative to continuously develop new technologies to detect foodborne pathogens and contaminants in order to aid the strengthening of healthcare and economic systems. In recent years, peptide-based sensors gained much attention in the field of food research as an alternative to immuno-, apta-, or DNA-based sensors. This review presents an overview of the electrochemical biosensors using peptides as molecular bio-recognition elements published mainly in the last decade, highlighting their possible application for rapid, non-destructive, and in situ analysis of food samples. Comparison with peptide-based optical and piezoelectrical sensors in terms of analytical performance is presented. Methods of foodstuffs pretreatment are also discussed.
Topics: Animals; Biosensing Techniques; DNA; Electric Impedance; Electrochemical Techniques; Escherichia coli; Food Contamination; Food Microbiology; Food Safety; Humans; Listeria monocytogenes; Microfluidics; Molecular Conformation; Oxidation-Reduction; Peptides; Potentiometry; Quality Control
PubMed: 34071841
DOI: 10.3390/molecules26113200 -
Analytical Chemistry Jun 2023Here, we have developed and applied a triple-barrel microelectrode. This device incorporates a platinum disk working electrode, a platinum disk counter electrode, and a...
Here, we have developed and applied a triple-barrel microelectrode. This device incorporates a platinum disk working electrode, a platinum disk counter electrode, and a low-leakage Ag/AgCl reference electrode into a small probe. We demonstrate that the incorporated low-leakage reference electrode shows similar voltammetry, potentiometry, and drift when compared to a commercial reference electrode in bulk solution. We also demonstrate the versatility of such a small three-channel system via voltammetry in nanoliter droplets and through electroanalysis of captured aerosols. Finally, we demonstrate the probe's potential utility in single-cell electroanalysis by making measurements within salmon eggs.
PubMed: 37218147
DOI: 10.1021/acs.analchem.3c00735 -
Sensors (Basel, Switzerland) Jan 2019Wearable potentiometric sensors have received considerable attention owing to their great potential in a wide range of physiological and clinical applications,... (Review)
Review
Wearable potentiometric sensors have received considerable attention owing to their great potential in a wide range of physiological and clinical applications, particularly involving ion detection in sweat. Despite the significant progress in the manner that potentiometric sensors are integrated in wearable devices, in terms of materials and fabrication approaches, there is yet plenty of room for improvement in the strategy adopted for the sample collection. Essentially, this involves a fluidic sampling cell for continuous sweat analysis during sport performance or sweat accumulation via iontophoresis induction for one-spot measurements in medical settings. Even though the majority of the reported papers from the last five years describe on-body tests of wearable potentiometric sensors while the individual is practicing a physical activity, the medical utilization of these devices has been demonstrated on very few occasions and only in the context of cystic fibrosis diagnosis. In this sense, it may be important to explore the implementation of wearable potentiometric sensors into the analysis of other biofluids, such as saliva, tears and urine, as herein discussed. While the fabrication and uses of wearable potentiometric sensors vary widely, there are many common issues related to the analytical characterization of such devices that must be consciously addressed, especially in terms of sensor calibration and the validation of on-body measurements. After the assessment of key wearable potentiometric sensors reported over the last five years, with particular attention paid to those for medical applications, the present review offers tentative guidance regarding the characterization of analytical performance as well as analytical and clinical validations, thereby aiming at generating debate in the scientific community to allow for the establishment of well-conceived protocols.
Topics: Biomedical Technology; Biosensing Techniques; Electrochemistry; Humans; Iontophoresis; Potentiometry; Wearable Electronic Devices
PubMed: 30658434
DOI: 10.3390/s19020363 -
Biosensors & Bioelectronics Jan 2023Electronic tongues (e-tongues) have been broadly employed in monitoring the quality of food, beverage, cosmetics, and pharmaceutical products, and in diagnosis of... (Review)
Review
Electronic tongues (e-tongues) have been broadly employed in monitoring the quality of food, beverage, cosmetics, and pharmaceutical products, and in diagnosis of diseases, as the e-tongues can discriminate samples of high complexity, reduce interference of the matrix, offer rapid response. Compared to other analytical approaches using expensive and complex instrumentation as well as required sample preparation, the e-tongue is non-destructive, miniaturizable and on-site method with little or no preparation of samples. Even though e-tongues are successfully commercialized, their application in cancer diagnosis from urine samples is underestimated. In this review, we would like to highlight the various analytical techniques such as Raman spectroscopy, infrared spectroscopy, fluorescence spectroscopy, and electrochemical methods (potentiometry and voltammetry) used as e-tongues for urine analysis towards non-invasive cancer diagnosis. Besides, different machine learning approaches, for instance, supervised and unsupervised learning algorithms are introduced to analyze extracted chemical data. Finally, capabilities of e-tongues in distinguishing between patients diagnosed with cancer and healthy controls are highlighted.
PubMed: 36272349
DOI: 10.1016/j.bios.2022.114810 -
Membranes May 2022In this study, the performance and long-time evaluation of solid-state composite (SSC) reference electrodes were investigated. The stability of all the SSC reference...
In this study, the performance and long-time evaluation of solid-state composite (SSC) reference electrodes were investigated. The stability of all the SSC reference electrodes was continuously monitored by using potentiometry and electrochemical impedance spectroscopy methods over a period of several months. A multi-solution protocol was used to study the influence of the ionic strength of the sample solution, ion charge, and mobility, and the sample pH values on the performance of the reference electrodes. The SSC reference electrodes were used in the calibration of commercial indicator electrodes for different ions at different temperatures. The concentrations of K, Na, Ca, and Cl ions and pH values were measured in river water samples at different temperatures using the SSC reference electrodes. The obtained results for the same samples were compared with the results given by an independent laboratory specialized in routine water analyses. The agreement between the results was very good and even better than the case where commercial reference electrodes were used. Our study showed that the SSC reference electrodes exhibit good long-term stability and excellent performance, both in the calibrations and analyses of environmental samples.
PubMed: 35736276
DOI: 10.3390/membranes12060569 -
Sensors (Basel, Switzerland) May 2022Direct potentiometric measurements using solid-state sensors have a great potential for thiabendazole (TBZ) determination, considering simplicity, accuracy, and low...
Direct potentiometric measurements using solid-state sensors have a great potential for thiabendazole (TBZ) determination, considering simplicity, accuracy, and low cost. Modifying the sensing material of the sensor with multi-walled carbon nanotubes (MWCNTs) leads to improved analytical properties of the sensor. In this study, a new potentiometric solid-state sensor for TBZ determination, based on MWCNTs modified with a sulfate group, and TBZ ion as sensing material was developed. The sensor exhibited a Nernstian response for TBZ (60.4 mV/decade of activity) in a working range between 8.6 × 10 and 1.0 × 10 M. The detection limit for TBZ was 6.2 × 10 M. The response time of the sensor for TBZ was 8 s, and its signal drift was only 1.7 mV/h. The new sensor is applicable for direct potentiometric determination of TBZ in complex real samples, such as fruit peel. The accuracy of TBZ determination is confirmed using the standard addition method.
Topics: Electrodes; Nanotubes, Carbon; Potentiometry; Smart Materials; Thiabendazole
PubMed: 35632191
DOI: 10.3390/s22103785 -
Current Opinion in Electrochemistry Aug 2021Potentiometric biosensors are incredibly versatile tools with budding uses in industry, security, environmental safety, and human health. This mini-review on recent...
Potentiometric biosensors are incredibly versatile tools with budding uses in industry, security, environmental safety, and human health. This mini-review on recent (2018-2020) advances in the field of potentiometric biosensors is intended to give a general overview of the main types of potentiometric biosensors for novices while still providing a brief but thorough summary of the novel advances and trends for experienced practitioners. These trends include the incorporation of nanomaterials, graphene, and novel immobilization materials, as well as a strong push towards miniaturized, flexible, and self-powered devices for in-field or at-home use.
PubMed: 34056144
DOI: 10.1016/j.coelec.2021.100735