The Experts below are selected from a list of 13341 Experts worldwide ranked by ideXlab platform
Joseph Wang - One of the best experts on this subject based on the ideXlab platform.
-
opaa fluoride biosensor chip towards field detection of g type Nerve Agents
Sensors and Actuators B-chemical, 2020Co-Authors: Yugender K Goud, Rupesh K. Mishra, Steven P. Harvey, Hazhir Teymourian, Samar S Sandhu, Nicholas Tostado, Lee C Moore, Joseph WangAbstract:Abstract Sensor technology, particularly disposable, field-deployable devices offer considerable promise for addressing major security demands, in general, and in particular the urgent needs for selective and rapid field detection of highly toxic G-type organophosphate (OP) Nerve Agents. Herein, we report on the first example of a disposable electrochemical biosensor chip for decentralized field detection of diisopropyl fluorophosphate (DFP), as the simulant compound of G-type Nerve Agents (e.g., Sarin and Soman), based on the integration of an all-solid-state fluoride potentiometric transducer with the enzyme organophosphorus acid anhydrolase (OPAA) in connection to a hand-held potentiometric analyzer. Such solid-contact fluoride ion-selective electrodes were realized by comparing different fluoride ionophores to select the bis(fluorodioctylstannyl)methane molecule, along with systematic optimization of the experimental parameters. This first solid-contact fluoride detection chip displayed a favorable analytical performance, with near-Nernstian behavior at neutral pH in different buffers, high selectivity against various anions along with excellent reproducibility. Combining such desirable merits of the new fluoride sensor with the selective biocatalytic hydrolysis via an immobilized OPAA, to break the P F bond of G-type neurotoxins and release detectable fluoride ions, thereby enabled an attractive analytical performance. Both the fluoride and the Nerve-agent recognition layers have thus been systematically optimized. The resulting biosensor chip thus displays a fast, sensitive and selective response towards DFP (including efficient discrimination against OP pesticides), along with a wide dynamic range of 250–3000 μM. Key challenges towards developing the Nerve-agent detection chip were carefully addressed, including the pH incompatibility of the enzymatic and detection processes. By providing effective discrimination against common OP pesticides and minimizing related false alarms, the resultant disposable potentiometric biochip platform is expected to provide an instantaneous reliable warning of chemical attack and exposure towards a timely countermeasure action, and hence, would dramatically advance the protection of our military personnel.
-
continuous opioid monitoring along with Nerve Agents on a wearable microneedle sensor array
Journal of the American Chemical Society, 2020Co-Authors: Rupesh K. Mishra, Yugender K Goud, Chochanon Moonla, Mona A Mohamed, Farshad Tehrani, Hazhir Teymourian, Joseph WangAbstract:There are urgent needs for sensing devices capable of distinguishing between episodes of opioid overdose and Nerve agent poisoning. This work presents a wearable microneedle sensor array for minimally invasive continuous electrochemical detection of opioid (OPi) and organophosphate (OP) Nerve Agents on a single patch platform. The new multimodal microneedle sensor array relies on unmodified and organophosphorus hydrolase (OPH) enzyme-modified carbon paste (CP) microneedle electrodes for square wave voltammetric (SWV) detection of the fentanyl and Nerve agent targets, respectively. Such real-time simultaneous sensing provides distinct unique information, along with attractive analytical performance, including high sensitivity, selectivity, and stability, for real-time on-body OPi-OP analysis. The patch represents the first sensing device capable of continuously monitoring fentanyl down to the nanomolar level through a nanomaterial-based multilayered surface architecture. Applicability of the sensor array toward opioids screening is demonstrated for morphine and norfentanyl. Successful OPi-OP detection conducted in a skin-mimicking phantom gel demonstrates the suitability of the device for rapid on-body sensing. Such progress toward continuous minimally invasive transdermal analysis of drugs of abuse and Nerve Agents holds promise for rapid countermeasures for protecting soldiers, civilians, and healthcare personnel.
-
wearable potentiometric tattoo biosensor for on body detection of g type Nerve Agents simulants
Sensors and Actuators B-chemical, 2018Co-Authors: Rupesh K. Mishra, Abbas Barfidokht, Aleksandar Karajic, Juliane R Sempionatto, Joshua Wang, Joseph WangAbstract:Abstract A new wearable potentiometric tattoo biosensor for real-time on-body monitoring of G-type Nerve Agents simulant is described. The skin-worn flexible biosensor responds rapidly and selectively to the fluorine-containing organophosphates (OP) Nerve agent simulant diisopropyl fluorophosphate (DFP, a model OP analyte) in both liquid and vapor phases. The epidermal potentiometric OP biosensor relies on the pH-sensitive polyaniline (PANi) coating on a flexible printed transducer for monitoring the proton release during the enzymatic hydrolysis of DFP by enzyme organophosphate hydrolase (OPH). The sensing electrodes are screen printed on a temporary tattoo paper and are interfaced to a conformal electronic interface that provides wireless data transmission. The skin-worn OP potentiometric sensor can withstand severe mechanical strains without compromising its analytical performance. The biosensor displays a wide dynamic range, fast response and high selectivity towards DFP (including efficient discrimination against organophosphate pesticides), and good reproducibility. The attractive performance of the new wearable biosensor indicates considerable promise for on-body threat detection towards rapid warning regarding potential exposure to G-series Nerve Agents.
-
zirconia graphene oxide hybrid micromotors for selective capture of Nerve Agents
Chemistry of Materials, 2015Co-Authors: Virendra V Singh, Aida Martin, Kevin Kaufmann, Severina D S De Oliveira, Joseph WangAbstract:Self-propelled zirconia-graphene/Pt hybrid tubular micromotors, prepared by electrochemical template synthesis, are used for both high-affinity capture and isolation of Nerve Agents. The simultaneous electrochemical deposition of zirconia and reduced graphene oxide leads to high surface area with a needle-like zirconia microstructure. The attractive surface properties of graphene sheets are used as growth directing template for the electrochemical synthesis of high surface area of zirconia nanostructures for effective and selective binding of organophosphate compounds. Such selective binding is dramatically enhanced by the rapid movement of the motors and the corresponding bubble-induced solution mixing. The greatly increased fluid transport leads to a 15-fold faster remediation compared to the use of the static counterpart structures. The unique material properties allow the convenient alkaline regeneration of the micromotor surface, improving the cost effectiveness of this methodology. The new strategy ...
-
disposable carbon nanotube modified screen printed biosensor for amperometric detection of organophosphorus pesticides and Nerve Agents
Electroanalysis, 2004Co-Authors: Yuehe Lin, Joseph WangAbstract:A disposable carbon nanotube-based biosensor was successfully developed and applied to the detection of organophosphorus (OP) pesticides and Nerve Agents. The biosensors using acetycholinesterase (AChE)/choline oxidase (CHO) enzymes provided a high sensitivity, large linear range, and low detection limits for the analysis of OP compounds. Such characteristics may be attributed to the catalytic activity of carbon nanotube to promote the redox reaction of hydrogen peroxide produced during AChE/CHO enzymatic reactions with their substrate, as well as the large surface area of carbon nanotube materials.
Rupesh K. Mishra - One of the best experts on this subject based on the ideXlab platform.
-
opaa fluoride biosensor chip towards field detection of g type Nerve Agents
Sensors and Actuators B-chemical, 2020Co-Authors: Yugender K Goud, Rupesh K. Mishra, Steven P. Harvey, Hazhir Teymourian, Samar S Sandhu, Nicholas Tostado, Lee C Moore, Joseph WangAbstract:Abstract Sensor technology, particularly disposable, field-deployable devices offer considerable promise for addressing major security demands, in general, and in particular the urgent needs for selective and rapid field detection of highly toxic G-type organophosphate (OP) Nerve Agents. Herein, we report on the first example of a disposable electrochemical biosensor chip for decentralized field detection of diisopropyl fluorophosphate (DFP), as the simulant compound of G-type Nerve Agents (e.g., Sarin and Soman), based on the integration of an all-solid-state fluoride potentiometric transducer with the enzyme organophosphorus acid anhydrolase (OPAA) in connection to a hand-held potentiometric analyzer. Such solid-contact fluoride ion-selective electrodes were realized by comparing different fluoride ionophores to select the bis(fluorodioctylstannyl)methane molecule, along with systematic optimization of the experimental parameters. This first solid-contact fluoride detection chip displayed a favorable analytical performance, with near-Nernstian behavior at neutral pH in different buffers, high selectivity against various anions along with excellent reproducibility. Combining such desirable merits of the new fluoride sensor with the selective biocatalytic hydrolysis via an immobilized OPAA, to break the P F bond of G-type neurotoxins and release detectable fluoride ions, thereby enabled an attractive analytical performance. Both the fluoride and the Nerve-agent recognition layers have thus been systematically optimized. The resulting biosensor chip thus displays a fast, sensitive and selective response towards DFP (including efficient discrimination against OP pesticides), along with a wide dynamic range of 250–3000 μM. Key challenges towards developing the Nerve-agent detection chip were carefully addressed, including the pH incompatibility of the enzymatic and detection processes. By providing effective discrimination against common OP pesticides and minimizing related false alarms, the resultant disposable potentiometric biochip platform is expected to provide an instantaneous reliable warning of chemical attack and exposure towards a timely countermeasure action, and hence, would dramatically advance the protection of our military personnel.
-
continuous opioid monitoring along with Nerve Agents on a wearable microneedle sensor array
Journal of the American Chemical Society, 2020Co-Authors: Rupesh K. Mishra, Yugender K Goud, Chochanon Moonla, Mona A Mohamed, Farshad Tehrani, Hazhir Teymourian, Joseph WangAbstract:There are urgent needs for sensing devices capable of distinguishing between episodes of opioid overdose and Nerve agent poisoning. This work presents a wearable microneedle sensor array for minimally invasive continuous electrochemical detection of opioid (OPi) and organophosphate (OP) Nerve Agents on a single patch platform. The new multimodal microneedle sensor array relies on unmodified and organophosphorus hydrolase (OPH) enzyme-modified carbon paste (CP) microneedle electrodes for square wave voltammetric (SWV) detection of the fentanyl and Nerve agent targets, respectively. Such real-time simultaneous sensing provides distinct unique information, along with attractive analytical performance, including high sensitivity, selectivity, and stability, for real-time on-body OPi-OP analysis. The patch represents the first sensing device capable of continuously monitoring fentanyl down to the nanomolar level through a nanomaterial-based multilayered surface architecture. Applicability of the sensor array toward opioids screening is demonstrated for morphine and norfentanyl. Successful OPi-OP detection conducted in a skin-mimicking phantom gel demonstrates the suitability of the device for rapid on-body sensing. Such progress toward continuous minimally invasive transdermal analysis of drugs of abuse and Nerve Agents holds promise for rapid countermeasures for protecting soldiers, civilians, and healthcare personnel.
-
wearable potentiometric tattoo biosensor for on body detection of g type Nerve Agents simulants
Sensors and Actuators B-chemical, 2018Co-Authors: Rupesh K. Mishra, Abbas Barfidokht, Aleksandar Karajic, Juliane R Sempionatto, Joshua Wang, Joseph WangAbstract:Abstract A new wearable potentiometric tattoo biosensor for real-time on-body monitoring of G-type Nerve Agents simulant is described. The skin-worn flexible biosensor responds rapidly and selectively to the fluorine-containing organophosphates (OP) Nerve agent simulant diisopropyl fluorophosphate (DFP, a model OP analyte) in both liquid and vapor phases. The epidermal potentiometric OP biosensor relies on the pH-sensitive polyaniline (PANi) coating on a flexible printed transducer for monitoring the proton release during the enzymatic hydrolysis of DFP by enzyme organophosphate hydrolase (OPH). The sensing electrodes are screen printed on a temporary tattoo paper and are interfaced to a conformal electronic interface that provides wireless data transmission. The skin-worn OP potentiometric sensor can withstand severe mechanical strains without compromising its analytical performance. The biosensor displays a wide dynamic range, fast response and high selectivity towards DFP (including efficient discrimination against organophosphate pesticides), and good reproducibility. The attractive performance of the new wearable biosensor indicates considerable promise for on-body threat detection towards rapid warning regarding potential exposure to G-series Nerve Agents.
Weiping Cai - One of the best experts on this subject based on the ideXlab platform.
-
sers based ultrasensitive detection of organophosphorus Nerve Agents via substrate s surface modification
Journal of Hazardous Materials, 2017Co-Authors: Qian Zhao, Guangqiang Liu, Hongwen Zhang, Fei Zhou, Weiping CaiAbstract:Highly efficient detection of the organicphosphor Nerve Agents such as sarin and soman, based on surface enhanced Raman scattering (SERS) effect, has been in challenge due to their weak adsorption property on coin metals. In this paper, a new strategy is presented to achieve the SERS-based ultrasensitive detection of sarin-simulated agent methanephosphonic acid (MPA) via the surface modification of SERS-substrates. The Au-coated Si nanocone array is surface-modified with 2-aminoethanethiol and used as SERS-substrate for detection of MPA. It has been shown that the modified substrate could preferentially capture MPA molecules in the solution with coupling agent and induce amidation reaction. The reaction products are still bound or anchor on the substrate's surface. The MPA molecules can thus be detected by Raman spectral measurement of the solution-soaked SERS-substrate. The minimum detection level is down to ∼1ppb. The Raman peak intensity versus the MPA concentration is subject to a linear double logarithmic relation from ∼1ppb to ∼1000ppm, which is attributed to Freundlich adsorption of MPA on the surface-modified SERS substrate. This study provides a new way for the highly efficient SERS-based detection of the organophosphorus Nerve Agents and some other target molecules weakly interacted with metal substrates.
Jean-pierre Simonato - One of the best experts on this subject based on the ideXlab platform.
-
chemical functionalization of electrodes for detection of gaseous Nerve Agents with carbon nanotube field effect transistors
Chemical Communications, 2011Co-Authors: Michael Delalande, Simon Clavaguera, Alexandre Carella, Momar Toure, Stephane Lenfant, D Deresmes, Dominique Vuillaume, Jean-pierre SimonatoAbstract:An innovative sensor for the detection of Nerve Agents in the gas phase based on a carbon nanotube field-effect transistor was developed. A high sensitivity to organophosphorus gases was obtained by modifying gold electrodes with specific tailor-made self-assembled monolayers.
-
Development of an autonomous detector for sensing of Nerve Agents based on functionalized silicon nanowire field-effect transistors
Talanta, 2011Co-Authors: Simon Clavaguera, Nicolas Raoul, Alexandre Carella, Michael Delalande, Caroline Celle, Jean-pierre SimonatoAbstract:The ability to detect minute traces of chemical warfare Agents is mandatory both for military forces and homeland security. Various detectors based on different technologies are available but still suffer from serious drawbacks such as false positives. There is still a need for the development of innovative reliable sensors, in particular for organophosphorus Nerve Agents like Sarin. We report herein on the fabrication of a portable, battery-operated, microprocessor-based prototype sensor system relying on silicon nanowire field-effect transistors for the detection of Nerve Agents. A fast, supersensitive and highly selective detection of organophosphorus molecules is reported. The results show also high selectivity in complex mixtures and on contaminated materials.
Kamil Kuca - One of the best experts on this subject based on the ideXlab platform.
-
SAR study to find optimal cholinesterase reactivator against organophosphorous Nerve Agents and pesticides
Archives of Toxicology, 2016Co-Authors: Lukas Gorecki, Jan Korabecny, Kamil Musilek, David Malinak, Eugenie Nepovimova, Rafael Dolezal, Ondrej Soukup, Kamil KucaAbstract:Irreversible inhibition of acetylcholinesterase (AChE) by organophosphates leads to many failures in living organism and ultimately in death. Organophosphorus compounds developed as Nerve Agents such as tabun, sarin, soman, VX and others belong to the most toxic chemical warfare Agents and are one of the biggest threats to the modern civilization. Moreover, misuse of Nerve Agents together with organophosphorus pesticides (e.g. malathion, paraoxon, chlorpyrifos, etc.) which are annually implicated in millions of intoxications and hundreds of thousand deaths reminds us of insufficient protection against these compounds. Basic treatments for these intoxications are based on immediate administration of atropine and acetylcholinesterase reactivators which are currently represented by mono- or bis-pyridinium aldoximes. However, these antidotes are not sufficient to ensure 100 % treatment efficacy even they are administered immediately after intoxication, and in general, they possess several drawbacks. Herein, we have reviewed new efforts leading to the development of novel reactivators and proposition of new promising strategies to design novel and effective antidotes. Structure–activity relationships and biological activities of recently proposed acetylcholinesterase reactivators are discussed and summarized. Among further modifications of known oximes, the main attention has been paid to dual binding site ligands of AChE as the current mainstream strategy. We have also discussed new chemical entities as potential replacement of oxime functional group.
-
Behavioral Toxicity of Nerve Agents
Handbook of Toxicology of Chemical Warfare Agents, 2015Co-Authors: Jiri Kassa, Kamil Kuca, Jiri Bajgar, Daniel JunAbstract:The behavioral changes belong to the most important and frequent symptoms of acute and delayed toxicity of organophosphorus (OP) Nerve Agents. The incidence of behavioral effects is higher in individuals who have been severely exposed to Nerve Agents, but they may occur in individuals who have received low-level exposure below those producing convulsions and other severe clinical signs of toxicity. The behavioral effects usually start within a few hours and last from several days to several weeks or months. The most frequent symptoms include disruption of cognitive functions, feelings of uneasiness, tenseness, and fatigue. Persistent severe alteration in behavior and cognitive functions, especially impairment of learning and memory, was observed after the exposure to high doses of Nerve Agents as a result of severe brain neuropathology that involves neuronal degeneration and necrosis of various brain regions, including the hippocampus that is connected with the alteration of cognitive functions. Nevertheless, repeated or long-term exposure to low levels of Nerve Agents can also cause behavioral alterations due to downregulation of muscarinic receptors in the hippocampus as a reaction on acetylcholine accumulation at muscarinic receptor sites based on acetylcholinesterase inhibition.
-
Monitoring of Blood Cholinesterase Activity in Workers Exposed to Nerve Agents
Handbook of Toxicology of Chemical Warfare Agents, 2015Co-Authors: Daniel Jun, Kamil Kuca, Jiri Bajgar, Jiri KassaAbstract:Nerve Agents are organophosphorus compounds influencing cholinergic Nerve transmission via inhibition of acetylcholinesterase (AChE; EC 3.1.1.7). The symptoms of intoxication include nicotinic, muscarinic, and central symptoms. Cholinesterases (ChEs; AChE and butyrylcholinesterase [BChE] EC 3.1.1.8) are characterized as the main enzymes involved in the toxic effect of these compounds including molecular forms. The activity of both enzymes is influenced by inhibitors and other factors such as their pathological states. The determination of ChEs is a key diagnostic tool in the diagnosis of poisoning with ChE inhibitors (OPs, Nerve Agents, and carbamates). For Nerve agent intoxication, AChE in red blood cells is more diagnostically important than BChE activity in plasma. There are several methods for ChE determination; however, the most frequent is the Ellman’s method and its modifications based on the hydrolysis of thiocholine esters and after detection of the free SH-group of the released thiocholine. The diagnosis of OP or Nerve agent poisoning is based on anamnesis, the clinical status of the intoxicated organism, and on ChE determination in the blood.
-
Colorimetric dipstick for assay of organophosphate pesticides and Nerve Agents represented by paraoxon, sarin and VX
Talanta, 2010Co-Authors: Miroslav Pohanka, Jan Korabecny, Kamil Kuca, Jana Zdarova Karasova, Jiri Pikula, Ondrej Holas, Jiri CabalAbstract:A dipstick for fast assay of Nerve Agents and organophosphate pesticides was developed. Indicator pH papers were used as detectors. The principle of the assay is based on enzymatic hydrolysis of acetylcholine into acetic acid and choline by acetylcholinesterase. Acidification of the reaction medium due to accumulation of acetic acid was visible. The colour changed from dark red to yellow as the pH indicator recognized pH shift. Presence of an organophosphate pesticide or a Nerve agent results in irreversible inhibition of acetylcholinesterase intercepted on the dipstick. The inhibition stops the enzymatic reaction. The inhibition appears as no change of the medium pH. Three compounds were assayed: paraoxon-ethyl as representative organophosphate pesticides and Nerve Agents sarin and VX. The achieved limit of detection was 5 x 10(-8)M for paraoxon-ethyl and 5 x 10(-9)M for sarin and VX. Dipsticks were found stable for at least one month. Suitability of these dipsticks for routine assay is discussed.
-
Nerve Agents Assay Using Cholinesterase Based Biosensor
Electroanalysis, 2009Co-Authors: Miroslav Pohanka, Petr Dobes, Lucie Drtinova, Kamil KucaAbstract:Electrochemical biosensor based on electric eel acetylcholinesterase (AChE) (EC 3.1.1.7) was performed for assay of Nerve Agents – tabun, sarin, soman, cyclosarin, and VX. The biosensor used AChE as biorecognition element. The presence of Nerve Agents was accompanied by a strong inhibition of AChE activity. Enzyme activity is easily measurable by electrochemical oxidation of thiocholine created from acetylthiocholine (ATChCl) by AChE-catalyzed hydrolysis. The tested Nerve Agents were successfully assayed. The best limits of detection were achieved for sarin (5.88×10−10 M) and VX (8.51×10−10 M) after one-minute assay. The biosensor was found long term stable at low as well as laboratory temperature.
