Search for: organophosphate-pesticides
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    A smart-phone based ratiometric nanoprobe for label-free detection of methyl parathion

    , Article Sensors and Actuators, B: Chemical ; Volume 322 , 2020 Fahimi Kashani, N ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Elsevier B.V  2020
    The widespread use of pesticides in pest management has boosted the demands for developing highly sensitive probes for on-site monitoring. Herein we presented a sensitive enzyme-free ratiometric probe for determination of methyl parathion (MP), as an organophosphate pesticide using TGA-capped CdTe QDs and carbon dots (CDs). Unlike previous methods in which hydrolysis product of MP is instrumental in the response of the sensors, here, self-assembly of cetyltrimethylammonium bromide (CTAB) on the surface of non-modified yellow-emissive CdTe QDs facilitates the quenching of CTAB-QDs upon addition of MP while the fluorescence intensity of CDs remains constant. Using a smartphone, the ratiometric... 

    Design of a Colorimetric Sensor Array Based on Aggregation of Plasmonic Nanoparticles for Detection and discrimination of Phosalone, Thiometon and Prothioconazole Pesticides

    , M.Sc. Thesis Sharif University of Technology Koushkestani, Marjan (Author) ; Hormozi Nezhad, Mohammad Reza (Supervisor) ; Ghasemi, Forough (Co-Supervisor)
    The use of myriad pesticides in agriculture crops has promoted the demand of developing rapid and sensitive probes for the detection and discrimination of diverse pesticides, which are usually used together. In this work, a colorimetric sensor array has been designed for identification and discrimination of Thiometon (TM) and Phosalone (PS) as organophosphate pesticides and Prothioconazole (PC) as a triazole pesticide. For this purpose, two different plasmonic nanoparticles including unmodified gold nanoparticles (AuNPs) and unmodified silver nanoparticles (AgNPs) were used as sensing elements. The principle of the proposed strategy relied on the aggregation of AuNPs and AgNPs through the... 

    Gold-nanoparticle-based colorimetric sensor array for discrimination of organophosphate pesticides

    , Article Analytical Chemistry ; Volume 88, Issue 16 , 2016 , Pages 8099-8106 ; 00032700 (ISSN) Fahimi Kashani, N ; Hormozi Nezhad, M. R ; Sharif University of Technology
    American Chemical Society 
    There is a growing interest in developing high-performance sensors monitoring organophosphate pesticides, primarily due to their broad usage and harmful effects on mammals. In the present study, a colorimetric sensor array consisting of citrate-capped 13 nm gold nanoparticles (AuNPs) has been proposed for the detection and discrimination of several organophosphate pesticides (OPs). The aggregation-induced spectral changes of AuNPs upon OP addition has been analyzed with pattern recognition techniques, including hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA). In addition, the proposed sensor array has the capability to identify individual OPs or mixtures of them in... 

    ThThnated Development of a pH assisted AgNP-based colorimetric sensor Array for simultaneous identification of phosalone and azinphosmethyl pesticides

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 219 , 2019 , Pages 496-503 ; 13861425 (ISSN) Orouji, A ; Abbasi Moayed, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Elsevier B.V  2019
    Development of simple and rapid methods for identification of pesticides, due to their broad usage and harmful effects on mammals, has been known as a critical demand. Herein, we have introduced a silver nanoparticle (AgNP)based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM)and Phosalone (PS)pesticides. In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5)showed different aggregation behaviors. As a result of aggregation, the color and UV–Vis spectra of AgNPs changed differentially, leading to distinct response patterns for AM and PS. The aggregation induced spectral changes of AgNPs, were used to identify AM and PS... 

    Multiresidue determination of pesticides from aquatic media using polyaniline nanowires network as highly efficient sorbent for microextraction in packed syringe

    , Article Analytica Chimica Acta ; Volume 740 , 2012 , Pages 43-49 ; 00032670 (ISSN) Bagheri, H ; Alipour, N ; Ayazi, Z ; Sharif University of Technology
    A simple, rapid and sensitive method based on microextraction in packed syringe (MEPS), in combination with gas chromatography-mass spectrometry (GC-MS) was developed. Polyaniline (PANI) nanowires network was synthesized and used as sorbent of MEPS for the multiresidue determination of selected analytes from triazine, organochlrorine and organophosphorous pesticides in aqueous samples. The PANI nanowires network was prepared using soft template technique and its characterization was studied by scanning electron microscopy (SEM). The presence of micelles in this methodology showed to be an important parameter in shaping the growing polymer. Hexadecyltrimethylammonium bromide (HTAB) was used...