Figure - available from: ChemElectroChem
This content is subject to copyright. Terms and conditions apply.
Miniaturized sensor array chip for field detection of organophosphorus neurotoxins. (A) Spectrum of detectable OP threat analytes using the four‐sensor array comprising (i) OPAA/F‐ISE biosensor, (ii) MIP‐202/pH‐ISE sensor, (iii) UiO‐66/p‐NP sensor and (iv) AChE/ChOx/H2O2 biosensor; (B) Schematic of the four electrode‐modification protocols with the corresponding reagent layers used for fabricating the individual sensors; (C) OP analyte recognition and sensing mechanisms for the respective combinations of recognition layers and electrochemical transducers of the four‐sensor array, comprising (i) Hydrolytic degradation of F‐containing G‐type NA simulants catalyzed by an OPAA‐based enzymatic recognition layer, followed by potentiometric detection of the resultant F⁻ anions with an organotin fluoride ionophore‐based F‐ISE transducer (i. e., OPAA/F‐ISE biosensor), (ii) Hydrolytic degradation of G‐type NA simulants (X=F⁻ or Cl⁻) catalyzed by a MIP‐202(Zr)‐based catalytic recognition layer, followed by potentiometric detection of the resultant H⁺ ions with a hydrogen ionophore I‐based pH‐ISE transducer (i. e., MIP‐202/pH‐ISE sensor), (iii) Hydrolytic degradation of p‐NP‐containing OP pesticides (e. g., methyl paraoxon) using a UiO‐66(Zr)‐based catalytic recognition layer, followed by voltametric detection of the liberated p‐NP product (i. e., UiO‐66/p‐NP sensor), (iv) Biocatalytic conversion of acetylcholine chloride to betaine catalyzed by the AChE/ChOx enzyme cascade‐based recognition layer, followed by the detection of OP threat‐induced AChE inhibition based on the amperometric sensor response to the H2O2 byproduct (i. e., AChE/ChOx/H2O2 biosensor).
Source publication
Rapid and reliable detection of organophosphorus (OP) threats is essential for facilitating efficient and timely countermeasures. This work describes the design and operation of a miniaturized electrochemical sensor array chip, based on strategic coupling of diverse MOF‐based biomimetic and biocatalytic reagent layers (offering tunable OP target sp...
Citations
... OPs were formerly thought to be a safe alternative to OCs, but their widespread usage, accumulation, and exposure have caused severe toxicological consequences on organisms that are not targeted [105][106][107]. OP compound poisoning is a global health issue, causing over three million poisonings and 200 thousand fatalities yearly [13,[108][109][110]. ...
Monitoring agricultural toxins such as mycotoxins is crucial for a healthy society. High concentrations of these toxins lead to the cause of several chronic diseases; therefore, developing analytical systems for detecting/monitoring agricultural toxins is essential. These toxins are found in crops such as vegetables, fruits, food, and beverage products. Currently, screening of these toxins is mostly performed with sophisticated instrumentation such as chromatography and spectroscopy techniques. However, these techniques are very expensive and require extensive maintenance, and their availability is limited to metro cities only. Alternatively, electrochemical biomimetic sensing methodologies have progressed hugely during the last decade due to their unique advantages like point-of-care sensing, miniaturized instrumentations, and mobile/personalized monitoring systems. Specifically, affinity-based sensing strategies including immunosensors, aptasensors, and molecular imprinted polymers offer tremendous sensitivity, selectivity, and stability to the sensing system. The current review discusses the principal mechanisms and the recent developments in affinity-based sensing methodologies for the detection and continuous monitoring of mycotoxins and pesticides. The core discussion has mainly focused on the fabrication protocols, advantages, and disadvantages of affinity-based sensing systems and different exploited electrochemical transduction techniques.
... As will be illustrated in the following sections, we observed significant improvements in the catalytic CEES hydrolytic degradation (percent conversion and conversion rate) with MIP-202 versus the established UiO-66 [10,11] and HKUST-1 [12,13] MOF catalysts. This biomimetic MIP-202 catalyst was recently found attractive towards the potentiometric detection of G-type nerve agent (NA) simulants in connection to a fluoride ISE and pH-ISE, offering high thermal/storage stability, chemical stability and high scalability [3,16]. ...
... For developing a potentiometric CEES sensor, an aqueous 10 mM HEPES buffer solution was selected as the analytical medium, based on its established compatibility with the MOF-catalyzed hydrolysis of other CWA simulants [3,16]. Notably, the MIP-202 catalyst (a) outperformed its established MOF counterparts, UiO-66 (b) and HKUST-1 (c), in both sensitivity and response stability towards detection of 50-300 µM CEES in pH 7.4 (10 mM) aqueous HEPES buffer solution (Fig. 3D). ...
... The results of these studies will be reported in our future work. Our future research efforts shall also aim at integrating the MIP-202/Cl-ISE sensor with our recently developed OP threats sensor array chip [16], to expand our chemical threat detection and discrimination capabilities from G-type NAs and OP pesticides to blister agents. Additionally, we aim to employ the MIP-202/Cl-ISE sensor towards vapor-phase CEES detection, as well as CEES detection in unbuffered aqueous media by incorporating internal buffering agents with MIP-202 to boost the pH resiliency and catalytic efficiency of CEES hydrolysis. ...
Existing sensor devices for sulfur mustard (HD) detection are commonly bulky, sluggish in response, or not sensitive enough to detect HD contamination owing to its low aqueous solubility. Herein, we describe the development of a miniaturized catalytic electrochemical sensor, in both portable and wearable configurations, for the real-time, remote/on-site wireless detection of low micromolar levels of the HD simulant, 2-chloroethyl ethyl sulfide (CEES). The screen-printed CEES potentiometric sensor relies on coating a new solid-contact chloride ion-selective electrode (Cl-ISE) with a biomimetic zirconium metal-organic framework (Zr-MOF), MIP-202-based reagent layer for catalytic CEES hydrolysis and electrochemical detection of the liberated Cl anion. We describe and characterize the use of the green MIP-202 Zr-MOF towards such CEES hydrolysis, and demonstrate its superior catalytic performance versus the established MOF catalysts UiO-66 and HKUST-1 using proton nuclear magnetic resonance (¹H NMR) analysis. The attractive analytical performance of the resulting strip and textile-based sensors has been demonstrated for the detection of CEES contamination in multiphasic samples ranging from aqueous buffered solutions, drinking water to aqueous buffered aerosols.
Developing reliable sensors that accurately detect deadly chemical gases is critical to global security. Nerve agents are one of the most dangerous chemicals in the world and are often found in gaseous forms in the environment, which remain a challenge to detect because of their low levels. In this paper, a fluorescent probe based on a Zr-based metal-organic framework UiO-66-NH2 was proposed. The specific binding between the Zr-O site of UiO-66-NH2 and diethyl chlorophosphate (DCP) blocked the ligand-to-metal charge transfer (LMCT) process in UiO-66-NH2, thereby enabling the fluorescence turn-on detection of DCP. More importantly, a simple and portable hydrogel soft-solid platform (UiO-66-NH2@Aga) was constructed by incorporating UiO-66-NH2 into the formation process of agarose (Aga) hydrogel for fast and sensitive detection of gaseous DCP. When the hydrogel was exposed to a low concentration of DCP vapor, its fluorescence changed from colorless to bright blue, allowing visualization of the DCP gas for analysis. The UiO-66-NH2@Aga integrated solid-state platform showed an excellent response to DCP vapor in the detection range of 1.98 to 9.90 ppm and with a detection limit of 1.16 ppm. This work opened up a unique way to design a convenient, low cost and practical gas physical examination platform.
While fluoride ions (F⁻) are abundant across environmental and biological systems, common procedures and potentiometric sensors for quantifying aqueous F⁻ are inefficient, time‐consuming, and suffer from poor pH resiliency and high detection limits. Herein, this work reports a new di‐boronic acid‐functionalized ferrocene (FDBA) molecular receptor for noncovalent F⁻ recognition, toward the development of a solid‐state miniaturized voltammetric fluoride sensor capable of direct and reversible F⁻ detection in drinking water (DW) (pH 6) and community water (pH 7.6–9.1) over the µg L⁻¹–mg L⁻¹ range. The associated sensing mechanism is enabled by the conformational change of FDBA from the open (charge‐repelled) to closed (π‐dimerized) conformation, which is facilitated by the unique linkage of two electron‐accepting phenylboronic acid moieties with the electron‐donating ferrocene moiety using rigid conjugated amide linkers. The square wave voltammetric (SWV) oxidation current response of the FDBA‐based fluoride sensor is spectroscopically investigated, suggesting a combination of electrooxidation‐triggered conformational change of FDBA on a nanocarbon‐modified electrode, F⁻ anion–π interactions, and resulting electron transfer between F⁻ and FDBA. The performance of the voltammetric fluoride sensor is compared to that of a commercial liquid junction‐based fluoride ion‐selective electrode (F‐ISE), and of a solid‐contact (SC) F‐ISE sensor chip, demonstrating significant advantages versus traditional potentiometric F‐ISEs.
Energy‐autonomous wearable systems and wearable microgrids have been a focus of developing the next‐generation wearable electronics due to their ability to harvest energy and to fully support the sustainable operation of wearable electronics. However, existing bioenergy harvesters require complex and low‐efficiency voltage regulation circuitry and have not achieved reliable extended operation and energy storage. In this work, the first example of integrating sweat lactate biofuel cells with a rechargeable Zn–AgCl battery into a bioenergy module for regulation‐free, high‐efficiency, extended biochemical energy harvesting and storage is demonstrated. The integrated bioenergy module is able to operate at its best efficiency due to their matching operating potentials and is characterized by robust mechanical durability enduring over 1000 cycles of repeated tensile deformation, as well as the outstanding long‐term autonomous operation that harvest 2.9 J of energy overnight from 20 min of exercise without measurable self‐discharge. A fully integrated wearable electronic skin patch, powered by two such bioenergy modules, is developed to wirelessly perform continuous sweat pH, ascorbic acid, and lactate sensing. The presented bioenergy module, adapting the wearable microgrid design considerations, delivers a practical, high‐efficiency, and reliable solution for next‐generation wearable electronics that features compatible form factors, commensurate performance, and complementary characteristics.
