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ABSTRACT: A sensitive electrochemical stripping voltammetric biosensor is designed for organophosphate pesticides (OPs) based on solid-phase extraction (SPE) using Ni/Al layered double hydroxides (LDHs) modified glassy carbon electrode (labeled as Ni/Al-LDHs/GCE). The Ni/Al-LDHs as the host are highly efficient to capture OPs, which dramatically facilitates the enrichment of nitroaromatic OPs onto their surface and realizes the stripping voltammetric detection of OPs. The stripping voltammetric performances of methyl parathion (MP) intercalated into LDHs were evaluated by cyclic voltammetric and square-wave voltammetric (SWV) analysis. The combination of the host-guest supramolecular structure, SPE, and stripping voltammetry provides a fast, simple, and sensitive electrochemical method for detecting nitroaromatic OPs by using MP as a model. The stripping analysis is linear over the MP concentration ranges of 0.001-0.1 and 0.2-1.0 microg mL(-1) with a detection limit of 0.6 ng mL(-1) (S/N=3). The developed biosensor exhibits good reproducibility and acceptable stability. This study offers a new promising protocol for OPs analysis.
Biosensors & bioelectronics 08/2009; 25(2):493-6. · 5.43 Impact Factor
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ABSTRACT: We developed a simple strategy for designing a highly sensitive electrochemical biosensor for organophosphate pesticides (OPs) based on acetylcholinesterase (AChE) immobilized onto Au nanoparticles-polypyrrole nanowires composite film modifid glassy carbon electrode (labeled as AChE-Au-PPy/GCE). Where, the generated Au nanoparticles (AuNPs) were homogenously distributed onto the interlaced PPy nanowires (PPy NWs) matrix, constructing a three-dimensional porous network. This network-like nanocomposite not only provided a biocompatible microenvironment to keep the bioactivity of AChE, but also exhibited a strong synergetic effect on improving the sensing properties of OPs. The combination of AuNPs and PPyNWs greatly catalyzed the oxidation of the enzymatically generated thiocholine product, thus increasing the detection sensitivity. On the basis of the inhibition of OPs on the enzymatic activity of AChE, the conditions for OPs detection were optimized by using methyl parathion as a model OP compound. The inhibition of methyl parathion was proportional to its concentration ranging from 0.005 to 0.12 and 0.5 to 4.5 microgmL(-1). The detection limit was 2 ngmL(-1). The developed biosensor exhibited good reproducibility and acceptable stability. This study provides a new promise tool for analysis of organophosphate pesticides.
Biosensors & bioelectronics 12/2008; 24(7):2285-8. · 5.43 Impact Factor
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ABSTRACT: We developed a simple strategy for designing a sensitive electrochemical stripping voltammetric sensor for organophosphate pesticides (OPs) based on solid-phase extraction (SPE) using nanosized Pt intercalated Ni/Al layered double hydroxides (labeled as NanoPt-LDHs). By assembling NanoPt with LDHs together, the resulting NanoPt-LDHs are highly efficient to capture OPs. It dramatically facilitates the enrichment of OPs onto their surface and realizes the sensitive stripping voltammetric detection of methyl parathion (MP) as a model of OPs. The stripping analysis shows highly linear over MP concentration ranges of 0.001–0.15 and 0.3–1.0 μg mL− 1 with a detection limit of 0.6 ng mL–1 (S/N = 3). The combination of NanoPt, LDHs, SPE, and square-wave voltammetry (SWV) provides a fast, simple, and sensitive electrochemical method for OPs.
Electrochemistry Communications 12(11):1658-1661. · 4.86 Impact Factor
