The preparation and characterization of photo-responsive sol–gel materials for 2,4-dichlorophenoxyacetic acid by surface imprinting

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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Improving Surface Imprinting Effect by Reducing Nonspecific Adsorption on Non-imprinted Polymer Films for 2,4-D Herbicide Sensors

Chemosensors ◽

10.3390/chemosensors9030043 ◽

2021 ◽

Vol 9 (3) ◽

pp. 43

Author(s):

Jin Chul Yang ◽

Suck Won Hong ◽

Jinyoung Park

Keyword(s):

Morphological Changes ◽

Unit Weight ◽

Dichlorophenoxyacetic Acid ◽

Surface Imprinting ◽

Imprinted Polymer ◽

Nonspecific Adsorption ◽

Chemical Surface ◽

Silane Modification ◽

Silanized Silica ◽

2,4 Dichlorophenoxyacetic Acid

Surface imprinting used for template recognition in nanocavities can be controlled and improved by surface morphological changes. Generally, the lithographic technique is used for surface patterning concerning sensing signal amplification in molecularly imprinted polymer (MIP) thin films. In this paper, we describe the effects of silanized silica molds on sensing the properties of MIP films. Porous imprinted poly(MAA–co–EGDMA) films were lithographically fabricated using silanized or non-treated normal silica replica molds to detect 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide as the standard template. The silanized mold MIP film (st-MIP) (Δf = −1021 Hz) exhibited a better sensing response than the non-treated normal MIP (n-MIP) (Δf = −978 Hz) because the imprinting effects, which occurred via functional groups on the silica surface, could be reduced through silane modification. Particularly, two non-imprinted (NIP) films (st-NIP and n-NIP) exhibited significantly different sensing responses. The st-NIP (Δfst-NIP = −332 Hz) films exhibited lower Δf values than the n-NIP film (Δfn-NIP = −610 Hz) owing to the remarkably reduced functionality against nonspecific adsorption. This phenomenon led to different imprinting factor (IF) values for the two MIP films (IFst-MIP = 3.38 and IFn-MIP = 1.86), which was calculated from the adsorbed 2,4-D mass per poly(MAA–co–EGDMA) unit weight (i.e., QMIP/QNIP). Moreover, it was found that the st-MIP film had better selectivity than the n-MIP film based on the sensing response of analogous herbicide solutions. As a result, it was revealed that the patterned molds’ chemical surface modification, which controls the surface functionality of imprinted films during photopolymerization, plays a role in fabricating enhanced sensing properties in patterned MIP films.

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Preparation of Graphene/TiO2Composite Nanomaterials and Its Photocatalytic Performance for the Degradation of 2,4-Dichlorophenoxyacetic Acid

Journal of Nanomaterials ◽

10.1155/2016/5858906 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Donggen Huang ◽

Tianzi Yang ◽

Zhuanghong Mo ◽

Qin Guo ◽

Shuiqing Quan ◽

...

Keyword(s):

High Temperature ◽

Sol Gel ◽

Chemical Properties ◽

Hydrogen Atmosphere ◽

Raw Material ◽

Dichlorophenoxyacetic Acid ◽

Anoxic Water ◽

Field Environment ◽

2,4 Dichlorophenoxyacetic Acid ◽

Electrochemical Stripping

The graphene (GR) was prepared by an improved electrochemical stripping method using a high-purity graphite rod as raw material and high temperature heat reduction in hydrogen atmosphere, and the graphene/TiO2(GR/TiO2) composite nanomaterials were manufactured by the method of sol-gel and high temperature crystallization in hydrogen atmosphere using butyl titanate and electrolysis graphene as precursors. The physical and chemical properties of the composites had been characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer (UV-Vis), scanning electron microscopy (SEM), Transmission Electron Microscope (TEM), and specific surface area (SSA) by BET method. The photocatalytic properties of GR/TiO2composites nanomaterials in anoxic water were studied by using 2,4-dichlorophenoxyacetic acid (2,4-D) as probe. The results showed that graphite was well intercalated and peeled by a facile electrolysis method in different electric field environment; a well dispersed and rings structure of graphene was prepared by coupling ultrasound-assisted changing voltage electrochemical stripping technology. The as-prepared GR/TiO2composites had good performance for the photocatalytic degradation of 2,4-D in anoxic water; the chlorines were removed from benzene ring; the middle products of dichlorophenol, chlorophenol, phloroglucinol, and so forth were produced from the photocatalytic redox reaction of 2,4-D in anoxic water; parts of 2,4-D were decomposed completely, and CO2and H2O were produced.

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Characterization of diverse 2,4-dichlorophenoxyacetic acid-degradative plasmids isolated from soil by complementation.

Applied and Environmental Microbiology ◽

10.1128/aem.61.5.1691-1698.1995 ◽

1995 ◽

Vol 61 (5) ◽

pp. 1691-1698 ◽

Cited By ~ 98

Author(s):

E M Top ◽

W E Holben ◽

L J Forney

Keyword(s):

Dichlorophenoxyacetic Acid ◽

2,4 Dichlorophenoxyacetic Acid

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Slurry photodegradation of 2,4-dichlorophenoxyacetic acid: A comparative study of impregnated and sol–gel In2O3–TiO2 mixed oxide catalysts

Journal of Photochemistry and Photobiology A Chemistry ◽

10.1016/j.jphotochem.2007.07.005 ◽

2008 ◽

Vol 193 (2-3) ◽

pp. 266-270 ◽

Cited By ~ 50

Author(s):

V. Rodríguez-González ◽

A. Moreno-Rodríguez ◽

M. May ◽

F. Tzompantzi ◽

R. Gómez

Keyword(s):

Comparative Study ◽

Mixed Oxide ◽

Sol Gel ◽

Oxide Catalysts ◽

Dichlorophenoxyacetic Acid ◽

Mixed Oxide Catalysts ◽

2,4 Dichlorophenoxyacetic Acid

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Characterization of Hapten-Protein Conjugates: Antibody Generation and Immunoassay Development for Chlorophenoxyacetic Acid Pesticides

Journal of AOAC International ◽

10.1093/jaoac/92.6.1773 ◽

2009 ◽

Vol 92 (6) ◽

pp. 1773-1779 ◽

Cited By ~ 4

Author(s):

Robin C Boro ◽

K Vikas Singh ◽

C Raman Suri

Keyword(s):

Inhibitory Concentration ◽

Dichlorophenoxyacetic Acid ◽

Protein Conjugation ◽

Protein Conjugates ◽

Highly Sensitive ◽

Ic50 Values ◽

Chlorophenoxyacetic Acid ◽

2,4 Dichlorophenoxyacetic Acid

Abstract The generation of specific and sensitive antibodies against small molecules is greatly dependent upon the characteristics of the hapten-protein conjugates. In this study, we report a new fluorescence-based method for the characterization of hapten-protein conjugates. The method is based on an effect promoted by hapten-protein conjugation density upon the fluorescence intensity of the intrinsic tryptophan chromophore molecules of the protein. The proposed methodology is applied to quantify the hapten-protein conjugation density for two different chlorophenoxyacetic acid pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenoxybutyric acid (2,4-DB), coupled to carrier protein. Highly sensitive anti-2,4-D and anti-2,4-DB antibodies were obtained using these well-characterized hapten-protein conjugates. The generated antibodies were used in an immunoassay format demonstrating inhibitory concentration (IC50) values equal to 30 and 7 ng/mL for 2,4-D and 2,4-DB, respectively. Linearity was observed in the concentration range between 0.1500 ng/mL with LODs around 4 and 3 ng/mL for 2,4-D and 2,4-DB, respectively, in standard water samples. The proposed method was successfully applied for the determination of the extent of hapten-protein conjugation to produce specific antibodies for immunoassay development against pesticides.

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