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- Bisphenol A (8) (entfernen)
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BPA is a chemical commonly used in the production of polymer-based materials that can have detrimental effects on the thyroid gland and impact human reproductive health. Various expensive methods, such as liquid and gas chromatography, have been suggested for detecting BPA.
The fluorescence polarization immunoassay (FPIA) is an inexpensive and efficient homogeneous mix-and-read method that allows for high-throughput screening. FPIA offers high specificity and sensitivity and can be carried out in a single phase within a timeframe of 20–30 min. In this study, new tracer molecules were designed that linked the fluorescein fluorophore with and without a spacer to the bisphenol A moiety. To assess the influence of the C6 spacer on the sensitivity of an assay based on the respective antibody, hapten–protein conjugates were synthesized and assessed for performance in an ELISA setup, and this resulted in a highly sensitive assay with a detection limit of 0.05 µg/L. The lowest limit of detection was reached by employing the spacer derivate in the FPIA and was 1.0 µg/L, working range from 2 to 155 µg/L. The validation of the methods was conducted using actual samples compared to LC–MS/MS, which served as the reference method. The FPIA and ELISA both demonstrated satisfactory concordance.
One of the most important chemicals used in the production of polymer plastics and coatings is bisphenol A. However, despite the large number of studies on the toxicity and hormonal activity of BPA, there are still open questions and thus considerable media attention regarding BPA toxicity. Hence, it is necessary to develop a sensitive, simple, cost-efficient, specific, portable, and rapid method for monitoring bisphenol A and for high sample throughput and on-site screening analysis. Lateral flow immunoassays have potential as rapid tests for on-site screening. To meet sensitivity criteria, they must be carefully optimized. A latex microparticle-based LFIA for detection of BPA was developed. The sensitivity of the assay was improved by non-contact printing of spot grids as the control and test lines with careful parameter optimization. Results of the test could be visually evaluated within 10 min with a visual cut-off of 10 µg/L (vLOD). Alternatively, photographs were taken, and image analysis performed to set up a calibration, which allowed for a calculated limit of detection (cLOD) of 0.14 µg/L. The method was validated for thermal paper samples against ELISA and LC–MS/MS as reference methods, showing good agreement with both methods
Singlet oxygen generation potential of two novel free-base-porphyrin photocatalysts was investigated. The freebase-porphyrin-sensitized Fe3O4 magnetic nanoparticles (MNPs) were tested for the degradation of the model pollutant Bisphenol A (BPA) in aqueous solution, for the first time. MNPs with either cubic or spherical shape were synthesized using the sonochemical approach, followed by sensitizing with photoactive 4,4′,4′′,4′′′- (Porphine-5,10,15,20-tetrayl)tetrakis(benzoic acid) (TCPP). The resulted photocatalysts were characterized in detail by scanning and transmission electron microscopy, Brunauer–Emmett–Teller analysis, spectral techniques and vibrating sample magnetometry. The electron spin resonance experiments have confirmed the high activity of the photocatalysts through the efficient formation of singlet oxygen in solution. The optimum operational parameters for BPA degradation were established as follows: 1.0 μmol L−1 BPA, 1.0 g L−1 of photocatalyst, 100 μmol L−1 H2O2, under UVA irradiation. In these conditions, the results for both photocatalysts revealed that after only 10 min of reaction, over 64% and ca. 90% of BPA have been removed from solution in the absence and presence of H2O2, respectively. Whereas after 60 minutes of treatment, only 24% of BPA in real wastewater effluent samples were removed under UVA irradiation in the absence of H2O2, showing the high complexity of real wastewater. Moreover, both photocatalysts were successfully used for BPA removal in three consecutive runs, without significant loss of catalytic features.
Cost-effective water cleaning approaches using improved Treatment technologies, for instance based on catalytic processes with high activity catalysts, are urgently needed. The aim of our study was to synthesize efficient Fenton-like photo-catalysts for rapid degradation of persistent organic micropollutants in aqueous medium. Iron-based nanomaterials were chemically synthesized through simple procedures by immobilization of either iron(II) oxalate (FeO) or iron(III) citrate (FeC) on magnetite (M) nanoparticles stabilized with polyethylene glycol (PEG). Various investigation techniques were performed in order to characterize the freshly prepared catalysts. By applying advanced oxidation processes, the effect of catalyst dosage, hydrogen peroxide concentration and UV-A light exposure were examined for Bisphenol A (BPA) conversion, at laboratory scale, in mild conditions. The obtained results revealed that BPA degradation was rapidly enhanced in the presence of low-concentration H2O2, as well as under UV-A light, and is highly dependent on the surface characteristics of the catalyst. Complete photo-degradation of BPA was achieved over the M/PEG/FeO catalyst in less than 15 minutes. Based on the catalytic performance, a hierarchy of the tested catalysts was established: M/PEG/FeO > M/PEG/FeC > M/PEG. The results of cytotoxicity assay using MCF-7 cells indicated that the aqueous samples after treatment are less cytotoxic.
The main goal of the study was to evaluate the catalytic activity of two hybrid nanocatalysts consisting in Fe3O4 nanoparticles modified with either chitosan (CS) or polyethylene glycol (PEG)/ferrous oxalate (FO), and further deposited on solid substrate as thin films. X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) were employed for the structural and morphological characterizations of the heterogeneous catalysts. The Degradation kinetic studies of two reactive azo dye (Reactive Black 5 (RB5) and Reactive Yellow 84 (RY84)) as well as Bisphenol A (BPA) solutions were carried out using Fenton-like oxidation, in the presence of different concentrations of H2O2, at initial near-neutral pH and room temperature. The results indicated that a low amount of catalytic material (0.15 g/L), deposited as thin film, was able to efficiently trigger dye degradation in solution in the presence of 6.5mmol/LH2O2 for RB5 and of only 1.6mmol/LH2O2 in the case of BPA and RY84. In the presence of complex matrices such asWWTP waters, the removal of BPAwas low (only 24% for effluent samples). Our findings recommend the studied immobilized nanocatalysts as promising economical tools for the pretreatment of wastewaters using advanced oxidation processes (AOPs).
Bisphenol A (BPA) is a common industrial chemical that is widely used as a monomer or additive in the production of polymer materials. This substance causes impairment of the childbearing function, acceleration of sexual aging, negatively impacts the brain, and also contributes to the development of certain oncological diseases, as well as increasing the risk of a fetus developing the Down syndrome. But the biggest downside of bisphenol is the fact that it accumulates in the system during its use, as well as after. Many methods have been proposed for the determination of BPA, in particular, gas and liquid chromatography. The main disadvantages of such approaches are the high cost of the equipment, the significant duration of an analysis, and difficulties in screening a large number of samples. Immunoanalytical techniques attributes are high throughput, high specificity and sensitivity, as well as low cost and simplicity. Particularly interesting as a quick test for screenings is the lateral flow immunoassay (LFIA), a format widely in use for the detection of pregnancy. LFIA for BPA have been described before, but lack sensitivity.
In this work, focuses on the conjugation (by passive adsorption) efficiency of the different monoclonal antibodies with 40 nm gold nanoparticles. The effect of factors such as pH value and concentration of antibody has been quantificationally discussed using spectra methods after adding 10% NaCl which induced gold nanoparticle aggregation. Consequently, 40 nm gold nanoparticles should be labeled with antibody under optimal pH value and optimal concentrations of antibody. It will be helpful for the application of antibody-labeled gold nanoparticles for the determination of bisphenol A in aqueous solutions (water from different sources, leachates and extracts).
Bisphenol A (BPA) is a common industrial chemical that is widely used as a monomer or additive in the production of polycarbonate plastics and other polymeric materials. The primary way of exposure to BPA for most people is assumed to be a direct con-tamination of food and water through use of containers, bottles, and other plastic stor-age. BPA has been identified as an important endocrine disrupting compound (EDC). It can interfere with hormonal activities like biosynthesis, metabolism and elimination of natural blood-borne hormones. Moreover, BPA can originate environmental problems. A spectrum of methods have been developed with the aim of determining BPA in water. Immunoassays appear to comply with sensitivity, rapidity, and low cost requirements for effective monitoring.
In this work a comparative analysis was conducted of the effect of temperature and the choice of buffers, as well as the substrate at various stages of an ELISA (enzyme-linked immunosorbent assay). The method has been optimized and has shown good repeatability and sensitivity. The results obtained from ELISA will be used as the basis for the development of a Lateral Flow ImmunoAssay (LFIA).
Three types of hybrid modified magnetite (Fe₃O₄) nanoparticles, functionalized with either chitosan, chitosan/iron (II) oxalate or chitosan/iron (III) citrate, were synthesized by chemical precipitation method.
The obtained nanomaterials were characterized by energy dispersive X-ray spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller analysis, scanning and Transmission electron microscopy, Fourier transform infrared spectroscopy and vibrating sample magnetometry. The prepared composites were further tested as magnetic catalysts for the removal of bisphenol A (BPA) in aqueous media. The kinetic Degradation experiments were performed at laboratory scale, while the best operational parameters for all three materials were established: 1.00 g L⁻¹ of catalyst, 10 mmol L⁻¹ H₂O₂, under simulated solar light irradiation.
After 15 min of UVA irradiation under the experimental conditions mentioned above, it was possible to decompose up to 99% of the micropollutant over all catalysts. Fe₃O₄/chitosan/iron oxalate catalyst showed the highest and fastest catalytic activity in BPA removal. Catalytic wet peroxide oxidation of non-biodegradable micropollutants on such iron-based hybrid nanoparticles can be a suitable pre-treatment method for wastewater decontamination, as an environment-friendly simplified Approach for water clean-up.