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1.
Analyst ; 149(2): 582, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38164701

RESUMO

Correction for 'CannibiSenS: an on-demand rapid screen for THC in human saliva' by Nathan Kodjo Mintah Churcher et al., Analyst, 2023, 148, 2921-2931, https://doi.org/10.1039/D3AN00522D.

2.
Mikrochim Acta ; 191(3): 146, 2024 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372811

RESUMO

Salmonella contamination is a major global health challenge, causing significant foodborne illness. However, current detection methods face limitations in sensitivity and time, which mostly rely on the culture-based detection techniques. Hence, there is an immediate and critical need to enhance early detection, reduce the incidence and impact of Salmonella contamination resulting in outbreaks. In this work, we demonstrate a portable non-faradaic, electrochemical sensing platform capable of detecting Salmonella in potable water with an assay turnaround time of ~ 9 min. We evaluated the effectiveness of this sensing platform by studying two sensor configurations: one utilizing pure gold (Au) and the other incorporating a semiconductor namely a zinc oxide thin film coated on the surface of the gold (Au/ZnO). The inclusion of zinc oxide was intended to enhance the sensing capabilities of the system. Through comprehensive experimentation and analysis, the LoD (limit of detection) values for the Au sensor and Au/ZnO sensor were 0.9 and 0.6 CFU/mL, respectively. In addition to sensitivity, we examined the sensing platform's precision and reproducibility. Both the Au sensor and Au/ZnO sensor exhibited remarkable consistency, with inter-study percentage coefficient of variation (%CV) and intra-study %CV consistently below 10%. The proposed sensing platform exhibits high sensitivity in detecting low concentrations of Salmonella in potable water. Its successful development demonstrates its potential as a rapid and on-site detection tool, offering portability and ease of use. This research opens new avenues for electrochemical-based sensors in food safety and public health, mitigating Salmonella outbreaks and improving water quality monitoring.


Assuntos
Água Potável , Óxido de Zinco , Reprodutibilidade dos Testes , Ouro , Salmonella
3.
Sensors (Basel) ; 24(4)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38400311

RESUMO

Soil is a vital component of the ecosystem that drives the holistic homeostasis of the environment. Directly, soil quality and health by means of sufficient levels of soil nutrients are required for sustainable agricultural practices for ideal crop yield. Among these groups of nutrients, soil carbon is a factor which has a dominating effect on greenhouse carbon phenomena and thereby the climate change rate and its influence on the planet. It influences the fertility of soil and other conditions like enriched nutrient cycling and water retention that forms the basis for modern 'regenerative agriculture'. Implementation of soil sensors would be fundamentally beneficial to characterize the soil parameters in a local as well as global environmental impact standpoint, and electrochemistry as a transduction mode is very apt due to its feasibility and ease of applicability. Organic Matter present in soil (SOM) changes the electroanalytical behavior of moieties present that are carbon-derived. Hence, an electrochemical-based 'bottom-up' approach is evaluated in this study to track soil organic carbon (SOC). As part of this setup, soil as a solid-phase electrolyte as in a standard electrochemical cell and electrode probes functionalized with correlated ionic species on top of the metalized electrodes are utilized. The surficial interface is biased using a square pulsed charge, thereby studying the effect of the polar current as a function of the SOC profile. The sensor formulation composite used is such that materials have higher capacity to interact with organic carbon pools in soil. The proposed sensor platform is then compared against the standard combustion method for SOC analysis and its merit is evaluated as a potential in situ, on-demand electrochemical soil analysis platform.

4.
Analyst ; 148(13): 2921-2931, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37306613

RESUMO

Management of substances that possess high potential for abuse requires a comprehensive understanding of the temporal effects of a corresponding volume of intake. Cannabis is deemed as one of the most widely used drugs in the United States and studies related to the primary psychoactive compound present in it, Δ-9-tetrahydrocannabinol (THC), have revealed that it causes adverse health effects. In this study, we present a field-deployable electrochemical sensing system that can detect THC at the 5 ng mL-1 cut-off level with a dynamic range of 0.1-100 ng mL-1 in human saliva. Considering the complexity of the human saliva matrix, the specificity study demonstrated selectivity towards THC with minimum interactions with ethanol and cannabidiol (CBD). Surface Plasmon Resonance (SPR) has been implemented to visualize and validate the capture probe as a means for THC detection. A robust, compatible binary classifier model has been shown in this work to effectively group samples into THC+ (high) and THC- (low) groups from human saliva with an accuracy greater than 90% considering a limited dataset. Hence, we demonstrate the potential of an innovative end-to-end system to effectively regulate cannabis use and prevent substance abuse in our surroundings.


Assuntos
Canabidiol , Cannabis , Humanos , Dronabinol/análise , Saliva/química , Cannabis/química , Canabidiol/análise
5.
Ecotoxicol Environ Saf ; 252: 114635, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36787687

RESUMO

In our daily life, as consumers we are constantly made aware of the impact of pesticides and other modifications to food products derived from genetically modified organisms (GMO's) that have an impact on human health. In our connected world, there is an immense interest for on-demand information about food quality prior to consumption. The gold standard method to detect pesticides or GMOs residues in food is complex and is not amenable to rapid consumer use. In this study, we demonstrate the feasibility of an electrochemical portable sensing approach for the simultaneous direct detection of spiked pesticides chlorpyrifos (Chlp) and GMOs protein Cry1Ab in real edamame soy matrix. The immunoassay based two-plex sensing platform was fabricated using respective antibody's Chlp on one side and Cry1Ab on other side. A simple lab-on-kitchen level preparation of matrix has been demonstrated and sensor response was tested using non-faradaic electrochemical impedance spectroscopy (EIS), which showed a linear response in Cry1Ab/Chlp concentrations from 0.3 ng/mL to 243 ng/mL with limit of detection 0.3 ng /mL for both the target antigens (Cry1Ab and Chlp) respectively. The spiked and recovery test results fall within ± 20% error in real sample matrix which demonstrates the performance of the our platform with maximum residue limit (MRL) for the given targets. Such electrochemical portable multi-analyte direct sensing tool with simple matrix processing protocol can be a future commercial field-testing tool for use at everyday consumer level.


Assuntos
Técnicas Biossensoriais , Clorpirifos , Nanopartículas Metálicas , Praguicidas , Humanos , Praguicidas/análise , Plantas Geneticamente Modificadas/metabolismo , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas , Nanopartículas Metálicas/química , Clorpirifos/metabolismo
6.
Anal Chem ; 94(30): 10617-10625, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35867902

RESUMO

Adulteration of medications is an emerging and significant threat to human health and well-being, even though adulterants are still often not considered seriously in clinical or forensic toxicology. Screening of drug adulterations is a major challenge and concern for regulatory authorities worldwide. Metformin hydrochloride, an important drug to treat diabetes, is found to be adulterated worldwide and a major reason to worry about the health and safety procedure. We have demonstrated a first-of-a-kind electrochemical biomedical device utilizing exfoliated graphene oxide (GO)─Nafion-modified customized gold screen-printed electrodes (spiral electrochemical notification-coupled electrode, SENCE), driven by electrochemical adsorptive stripping voltammetry, to identify the trace level adulteration in metformin. The GO-Nafion-SPE interface has been characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, and Fourier transform infrared. Custom-made screen-printed SENCEs have been functionalized with GO nanoparticles (transducer) to obtain a fingerprint signal response of metformin using differential pulse voltammetry. A linear calibrated dose response has been obtained with n = 3 repetitions with a low limit of detection of 10 ppm for metformin. We have used the sensing response as a function of adulteration, and it is extensively supported by rigorous statistical analysis along with the help of the machine learning tool. This is a first-of-its-kind IoT-enabled electrochemical sensor and analysis platform that can detect drug adulteration as a low, medium, and high output.


Assuntos
Técnicas Eletroquímicas , Metformina , Técnicas Eletroquímicas/métodos , Eletrodos , Ouro/química , Humanos , Limite de Detecção
7.
Langmuir ; 38(5): 1781-1790, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35089037

RESUMO

The toxicity levels of and exposure to glyphosate, a widely used herbicide and desiccant, are significant public health issues. In this study, we aim to design a highly sensitive, label-free, portable sensor for the direct detection of glyphosate in human urine. The sensor platform consists of a portable, printed circuit board circular platform with gold working and reference electrodes to enable nonfaradic electrochemical impedance spectroscopy. The sensing platform was an immunoassay-based, gold electrode surface immobilized with a monolayer of dithiobis(succinimidyl propionate) (DSP), a thiol-based cross-linker, which was then modified with a glyphosate antibody (Glyp-Ab) through the bonding of the ester group of DSP with the amide of the antibody (Glyp-Ab). The sensor was tested electrochemically, first using the laboratory-based benchtop method for the glyphosate-spiked urine samples, resulting in a dynamic response in the concentration range of 0.1-72 ng/mL with a limit of detection of 0.1 ng/mL. The platform showed high selectivity in the presence of major interfering analytes in urine [malathion (Mal), 3-phenoxybenzoic acid (PBA), and chlorpyrifos (Chlp)] and high reproducibility. The sensing platform was then translated into a portable device that showed a performance correlation (r = 0.994) with the benchtop (laboratory method). This developed portable sensing approach can be a highly reliable alternate sensor platform for the direct detection of pesticides in human bodily fluids.


Assuntos
Técnicas Biossensoriais , Praguicidas , Técnicas Eletroquímicas/métodos , Eletrodos , Glicina/análogos & derivados , Ouro , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Glifosato
8.
Mikrochim Acta ; 189(6): 231, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35612633

RESUMO

A novel electrochemical sensor is reported for the detection of isoprene levels in breath using a ZIF-based electrochemical nose. This sensor incorporates a hybrid detection system using gold nanoparticles encapsulated inside the ZIF-8 moiety. Breath-based analysis is widely being used for monitoring the metabolic state of the body. It is associated with the change in the concentration of volatile organic compounds and inorganic gases released endogenously and can be tracked using breath as the sample. One such volatile organic compound, isoprene, has been correlated to the presence of influenza virus or respiratory inflammation. Analytical techniques such as powder X-ray diffraction, scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and tunneling electron microscopy were used to understand the structural features of the composite. The electrochemical nose system uses chronoamperometry as the transduction mechanism to monitor the diffusion kinetics of the target analyte across the electrode-electrolyte interface. The presented work demonstrates isoprene sensing with high sensitivity and specificity and a detection limit of 10 parts per billion in air. We successfully demonstrate the functionality of the ZIF-based electrochemical nose for point-of-care screening of isoprene levels by developing a prototype device using a commercially available development board. We foresee that the developed sensing platform can help in early screening for the presence of influenza virus and help control the infection rate.


Assuntos
Ouro , Nanopartículas Metálicas , Biomarcadores , Testes Respiratórios , Eletrodos
9.
Sensors (Basel) ; 22(20)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36298107

RESUMO

In this work, we propose a novel diagnostic biosensor that can enable stratification of disease states based on severity and hence allow for clear and actionable diagnoses. The scheme can potentially boost current Point-Of-Care (POC) biosensors for diseases that require time-critical stratification. Here, two key inflammatory biomarkers­Interleukin-8 and Interleukin-6­have been explored as proof of concept, and a four-class stratification of inflammatory disease severity is discussed. Our method is superior to traditional lab techniques as it is faster (<4 minutes turn-around time) and can work with any combination of disease biomarkers to categorize diseases by subtypes and severity. At its core, the biosensor relies on electrochemical impedance spectroscopy to transduce subtle inflammatory stimuli at the input for IL-8 and IL-6 for a limit of detection (LOD) of 1 pg/mL each. The biosensing scheme utilizes a two-stage random forest machine learning model for 4-state output disease classification with a 98.437% accuracy. This scheme can potentially boost the diagnostic power of current electrochemical biosensors for better precision therapy and improved patient outcomes.


Assuntos
Técnicas Biossensoriais , Interleucina-8 , Humanos , Interleucina-6 , Técnicas Biossensoriais/métodos , Espectroscopia Dielétrica/métodos , Biomarcadores , Técnicas Eletroquímicas
10.
Analyst ; 146(11): 3482-3492, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33955985

RESUMO

Identification of diseases in sedentary populations on a timely basis before reaching a critical stage is a continuing challenge faced by emergency care centers. Lactate is a key biomarker for monitoring restricted oxygen supply essential for assessing the physiological responses of the user for clinical diagnostics. The novelty of this work is the development of a non-invasive, mediator-free, stick and remove biosensor for the on-demand measurement of lactate in passive sweat targeted towards sedentary populations. The conformable interface of the biosensors with skin can be engineered to extract relevant biochemical signals and quantify the in situ sweat biomarker levels. In this work, we demonstrate a highly sensitive and specific on-demand biosensor with a fabricated hybrid nanotextured Au/ZnO electrode stack embedded within a flexible nanoporous material to capture the temporal dynamics of passive sweat lactate. The biosensor exhibits a lactate specific response in human sweat with a 1 mM lower limit of detection and a wide dynamic detection range of 1-100 mM (R2 = 0.98). The proposed biosensor has a sensitivity of 8.3% mM-1 while selectivity studies reveal negative interactions with non-specific molecules. The sensor stability studies showed an ∼30% degradation in the lactate biosensing response over a 4-day duration when stored at 4 °C. Non-faradaic electrochemical spectroscopy is employed as the detection modality to quantify the enzymatic catalysis of sweat lactate at the electrode-sweat interface. Spectroscopic characterization techniques such as XPS, ATR-FTIR, and zeta potential measurements confirm the enzymatic assay binding efficacy on a qualitative scale.


Assuntos
Técnicas Biossensoriais , Ácido Láctico , Ensaios Enzimáticos , Humanos , Suor
11.
Analyst ; 145(3): 784-796, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31867585

RESUMO

Chronobiology is defined as the temporal fluctuations occurring in the human physiology due to the circadian cycle. These fluctuations are good indicators of the functioning of the Hypothalamic-Pituitary-Adrenal axis (HPA axis) and can be tracked by using biomarkers: cortisol and DHEA. Low volume tracking systems will be beneficial for patients exposed to chronic stress, patients suffering from endocrine conditions manifested by circadian disruption and act as a lifestyle monitoring tool. The sensor system demonstrated in this work was an affinity-based system, characterized using EIS (Electrochemical Impedance Spectroscopy).The sensor can detect cortisol and DHEA in the physiologically relevant ranges i.e. 8-200 ng ml-1 and 2-131 ng ml-1 respectively. Thus, the senor is a non-invasive, label free, cost-effective solution for tracking chronobiology for circadian diagnostics.


Assuntos
Biomarcadores/análise , Suor/metabolismo , Técnicas Biossensoriais/métodos , Desidroepiandrosterona/análise , Espectroscopia Dielétrica , Humanos , Hidrocortisona/análise , Concentração de Íons de Hidrogênio , Estilo de Vida , Suor/química
12.
Sensors (Basel) ; 20(4)2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32092938

RESUMO

Over the past few years, room-temperature ionic liquid (RTIL) has evolved as an important solvent-cum-electrolyte because of its high thermal stability and excellent electrochemical activity. Due to these unique properties, RTILs have been used as a solvent/electrolyte/mediator in many applications. There are many RTILs, which possess good conductivity as well as an optimal electrochemical window, thus enabling their application as a transducer for electrochemical sensors. Nitroaromatics are a class of organic compounds with significant industrial applications; however, due to their excess use, detection is a major concern. The electrochemical performance of a glassy carbon electrode modified with three different RTILs, [EMIM][BF4], [BMIM][BF4] and [EMIM][TF2N], has been evaluated for the sensing of two different nitroaromatic analytes: 2,6-dinitrotoluene (2,6 DNT) and ethylnitrobenzene (ENB). Three RTILs have been chosen such that they have either a common anion or cation amongst them. The sensory response has been measured using square wave voltammetry (SQWV). We found the transducing ability of [EMIM][BF4] to be superior compared to the other two RTILs. A low limit of detection (LOD) of 1 ppm has been achieved with a 95% confidence interval for both the analytes. The efficacy of varying the cationic and anionic species of RTIL to obtain a perfect combination has been thoroughly investigated in this work, which shows a novel selection process of RTILs for specific applications. Moreover, the results obtained from testing with a glassy carbon electrode (GCE) have been replicated using a miniaturized sensor platform that can be deployed easily for on-site sensing applications.

13.
Sensors (Basel) ; 19(20)2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31652574

RESUMO

This work demonstrates a novel electrochemical biosensor for the detection of chloride ion levels in ultra-low volumes (1-3 microliters) of passively expressed human sweat. We present here a hydration monitor that the pediatric, geriatric, and other immune-compromised or physically inactive/sedentary population cohort can utilize, for whom the current methods of chloride quantification of active stimulation of sweat glands through iontophoresis or treadmill runs are unsuitable. In this work, non-faradaic electroanalysis using gold microelectrodes deposited on a flexible nanoporous substrate, for high nanoscale surface area to volume enhancement, was leveraged to operate in ultra-low sweat volumes of <3 µL eluted at natural rates. The specific chloride ionophore-based affinity of chloride ions resulted in the modulation of charge transfer within the electrical double layer at the electrode-sweat buffer interface, which was transduced using electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Linear calibration dose responses with R-squared values of 0.9746 and 0.9403 for EIS and CA respectively were obtained for a dynamic range of 10-100 mM. The surface charge and the binding chemistry of the capture probe were studied using zeta potential studies and UV-Vis. The dynamic sweat chloride-tracking capability of the sensor was evaluated for a duration of 180 min. Studies were conducted to probe the efficacy of the developed sensor for passive ultra-low sweat chloride assessment on human subjects (n = 3).


Assuntos
Técnicas Biossensoriais , Cloretos/análise , Suor/química , Soluções Tampão , Calibragem , Espectroscopia Dielétrica , Técnicas Eletroquímicas , Humanos , Concentração de Íons de Hidrogênio , Eletricidade Estática
14.
Biochim Biophys Acta ; 1860(9): 1877-83, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27262539

RESUMO

Non-invasive real time methods for characterizing biomolecular events that contribute towards apoptotic kinetics would be of significant importance in the field of cancer biology. Effective drug-induced apoptosis is an important factor for establishing the relationship between cancer genetics and treatment sensitivity. The objective of this study was to develop a non-invasive technique to characterize cancer cells that are undergoing drug-induced apoptosis. We used dielectrophoresis to determine apoptotic cells as early as 2h post drug treatment as compared to 24h with standard flow cytometry method using non-small cell lung cancer (NSCLC) adenocarcinoma cell line (HCC1833) as a study model. Our studies have shown significant differences in apoptotic cells by chromatin condensation, formation of apoptotic bodies and exposure of phosphatidylserine (PS) on the extracellular surface when the cells where treated with a potent Bcl-2 family inhibitor drug (ABT-263). Time lapse dielectrophoretic studies were performed over 24h period after exposure to ABT-263 at clinically relevant concentrations. The dielectrophoretic studies were compared to Annexin-V FITC flow assay for the detection of PS in mid-stage apoptosis using flow cytometry. As a result of physical and biochemical changes, inherent dielectric properties of cells undergoing varying stages of apoptosis showed amplified changes in their cytoplasmic and membrane capacitance. In addition, zeta potential of these fixed isolated cells was measured to obtain direct correlation to biomolecular events.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Compostos de Anilina/farmacologia , Anexina A5/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/patologia , Cromatina/efeitos dos fármacos , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Eletroforese/métodos , Citometria de Fluxo/métodos , Humanos , Neoplasias Pulmonares/metabolismo , Fosfatidilserinas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sulfonamidas/farmacologia
15.
Langmuir ; 33(31): 7591-7599, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28742363

RESUMO

The effect of incorporating different types of carbon nanotubes into composite films of a redox polymer (FcMe2-C3-LPEI) and glucose oxidase (GOX) was investigated. The composite films were constructed by first forming a high-surface area network film of either single-walled carbon nanotubes (SWNTs) or multiwalled carbon nanotubes (MWNTs) on a glassy carbon electrode (GCE) by solution casting of a suspension of Triton-X-100 dispersed SWNTs. Next a glucose responsive redox hydrogel was formed on top of the nanotube-modified electrode by cross-linking FcMe2-C3-LPEI with glucose oxidase via ethylene glycol diglycidyl ether (EGDGE). Electrochemical and enzymatic measurements showed that composite films made with (7,6) SWNTs produced a higher response (3.3 mA/cm2) to glucose than films made with (6,5) SWNTs (1.8 mA/cm2) or MWNTs (1.2 mA/cm2) or films made without SWNTs (0.7 mA/cm2). We also show that the response of the composite films could be systematically varied by fabricating SWNT films with different weight ratios of (7,6) and (6,5) SWNTs. Optimization of the (7,6) SWNTs loading and the redox polymer-enzyme film produced a glucose response of 11.2 mA/cm2. Combining the optimized glucose films with a platinum oxygen breathing cathode into a biofuel cell produced a maximum power density output of 343 µW/cm2.

16.
Analyst ; 142(15): 2770-2780, 2017 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-28650005

RESUMO

An ultrasensitive aptasensor for the label free non-faradaic detection of thrombin has been demonstrated on molybdenum disulphide (MoS2) nanosheets. These nanosheets were physiochemically immobilized onto a silicon micro-electrode platform. Thrombin detection was achieved through the charge modulation of the electrical double layer due to the specific and dose dependent binding of thrombin to the surface of thiol terminated ssDNA aptamer functionalized MoS2 nanosheets. Electrical double layer charge modulation associated with thrombin binding was characterized using electrochemical impedance spectroscopy. Dynamic light scattering was also used to confirm the dose dependent behavior. ATR-FTIR spectroscopy and XPS analysis were independently used to validate the functionalization of the ssDNA aptamer onto MoS2 nanosheets. ssDNA aptamer functionalized molybdenum disulfide (MoS2) for selective and specific capture of thrombin was demonstrated both in phosphate buffered saline (PBS) and human serum. The optimized immunoassay enabled the detection of thrombin ranging from 267 fM to 267 pM in phosphate buffer. The limit of detection of 53 pM and the linear dynamic range of detection of thrombin ranged from 53 to 854 pM in human serum. The rapid response time for the electrochemical impedance spectroscopy signal makes it an attractive option for the real-time detection of thrombin based point-of-care diagnostic devices.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Espectroscopia Dielétrica , Trombina/análise , Dissulfetos , Eletrodos , Humanos , Molibdênio , Nanoestruturas
17.
ACS Appl Mater Interfaces ; 16(1): 190-200, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38153905

RESUMO

Opioids are considered to be a global threat, and we are facing the worst opioid crisis of the decade. Synthetic opioids like fentanyl are highly potent and deadly toward human body, and hence its detection is an inevitable requirement globally. Naloxone is known for its antagonist property toward fentanyl, and we performed computational simulations to find their interactions and use this principle to build the first of a kind impedimetric sensor device, transduced by 3D-ZIF-8 with in situ encapsulated naloxone-gold nanoparticles. The probe is synthesized using a unique encapsulation strategy, thoroughly characterized by various physicochemical and microscopic tools. The sensor is highly selective toward fentanyl and can detect fentanyl up to 100 ppm in a synthetic sample. A prototype device is also built based on the synthetic calibration and applied to the spiked urine sample, and the performance is evaluated using statistical and machine learning tools.


Assuntos
Nanopartículas Metálicas , Naloxona , Humanos , Fentanila , Ouro/química , Nanopartículas Metálicas/química , Analgésicos Opioides
18.
Biosensors (Basel) ; 14(6)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38920602

RESUMO

There is a pressing need to enhance early detection methods of E. coli O157:H7 to mitigate the occurrence and consequences of pathogenic contamination and associated outbreaks. This study highlights the efficacy of a portable electrochemical sensing platform that operates without faradaic processes towards detecting and quantifying E. coli O157:H7. It is specifically tailored for quick identification in potable water. The assay processing time is approximately 5 min, addressing the need for swift and efficient pathogen detection. The sensing platform was constructed utilizing specific, monoclonal E. coli antibodies, based on single-capture, non-faradaic, electrochemical immunoassay principles. The E. coli sensor assay underwent testing over a wide concentration range, spanning from 10 to 105 CFU/mL, and a limit of detection (LoD) of 1 CFU/mL was demonstrated. Significantly, the sensor's performance remained consistent across studies, with both inter- and intra-study coefficients of variation consistently below 20%. To evaluate real-world feasibility, a comparative examination was performed between laboratory-based benchtop data and data obtained from the portable device. The proposed sensing platform exhibited remarkable sensitivity and selectivity, enabling the detection of minimal E. coli concentrations in potable water. This successful advancement positions it as a promising solution for prompt on-site detection, characterized by its portability and user-friendly operation. This study presents electrochemical-based sensors as significant contributors to ensuring food safety and public health. They play a crucial role in preventing the occurrence of epidemics and enhancing the supervision of water quality.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Escherichia coli O157 , Microbiologia da Água , Escherichia coli O157/isolamento & purificação , Limite de Detecção , Imunoensaio
19.
Artigo em Inglês | MEDLINE | ID: mdl-37356818

RESUMO

Growing interest over recent years in personalized health monitoring coupled with the skyrocketing popularity of wearable smart devices has led to the increased relevance of wearable sweat-based sensors for biomarker detection. From optimizing workouts to risk management of cardiovascular diseases and monitoring prediabetes, the ability of sweat sensors to continuously and noninvasively measure biomarkers in real-time has a wide range of applications. Conventional sweat sensors utilize external stimulation of sweat glands to obtain samples, however; this stimulation influences the expression profile of the biomarkers and reduces the accuracy of the detection method. To address this limitation, our laboratory pioneered the development of the passive sweat sensor subfield, which allowed for our progress in developing a sweat chemistry panel. Passive sweat sensors utilize nanoporous structures to confine and detect biomarkers in ultra-low sweat volumes. The ability of passive sweat sensors to use smaller samples than conventional sensors enable users with sedentary lifestyles who perspire less to benefit from sweat sensor technology not previously afforded to them. Herein, the mechanisms and strategies of current sweat sensors are summarized with an emphasis on the emerging subfield of passive sweat-based diagnostics. Prospects for this technology include discovering new biomarkers expressed in sweat and expanding the list of relevant detectable biomarkers. Moreover, the accuracy of biomarker detection can be enhanced with machine learning using prediction algorithms trained on clinical data. Applying this machine learning in conjunction with multiplex biomarker detection will allow for a more holistic approach to trend predictions. This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Biosensing.


Assuntos
Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Suor/química , Suor/metabolismo , Biomarcadores/análise
20.
Sci Rep ; 14(1): 2833, 2024 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-38310197

RESUMO

Wearable devices can non-invasively monitor patients with chronic diseases. Sweat is an easily accessible biofluid for continuous sampling of analytes, including inflammatory markers and cytokines. We evaluated a sweat sensing wearable device in subjects with and without inflammatory bowel disease (IBD), a chronic inflammatory condition of the gastrointestinal tract. Participants with an IBD related hospital admission and a C-reactive protein level above 5 mg/L wore a sweat sensing wearable device for up to 5 days. Tumor necrosis factor-alpha (TNF-α) levels were continually assessed in the sweat via the sensor, and daily in the blood. A second cohort of healthy subjects without chronic diseases wore the device for up to 48 h. Twenty-eight subjects were enrolled. In the 16 subjects with IBD, a moderate linear relationship between serum and sweat TNF-α levels was observed (R2 = 0.72). Subjects with IBD were found to have a mean sweat TNF-α level of 2.11 pg/mL, compared to a mean value of 0.19 pg/mL in 12 healthy controls (p < 0.0001). Sweat TNF-α measurements differentiated subjects with active IBD from healthy subjects with an AUC of 0.962 (95% CI 0.894-1.000). A sweat sensing wearable device can longitudinally measure key sweat-based markers of IBD. TNF-α levels in the sweat of subjects with IBD correlate with serum values, suggesting feasibility in non-invasive disease monitoring.


Assuntos
Doenças Inflamatórias Intestinais , Dispositivos Eletrônicos Vestíveis , Humanos , Fator de Necrose Tumoral alfa , Suor , Doenças Inflamatórias Intestinais/diagnóstico , Doença Crônica
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