A cloth-based analytical device combined with electrochemiluminescence detection (CAD–ECL) was described for rapid determination of histamine (HA). The CAD device was produced by screen-printing a ...conductive carbon ink onto a patterned hydrophobic electrochemical microfluidic chamber to fabricate the three-carbon electrode system on a single hydrophilic cloth. The introduction of carbon nanodots linked to chitosan on the working carbon electrode surface enhanced the catalytic performance and overcame the resistance of the cotton fiber material. On this basis, the enhancement of the electrochemiluminescence (ECL) signal of the tris(2,2′-bipyridyl) ruthenium(II) complex, caused by HA, was observed in a phosphate buffer solution at pH 7.6. The proposed CAD–ECL sensor was successfully applied to the quantification of HA in fish and fishery samples with good linearity between ECL intensity and the logarithm of HA concentration in the range 1.0 to 1000.0 µg L
−1
with a low detection limit of 0.82 µg L
−1
.
Graphical abstract
Crystalline TiO₂ has shown its great photocatalytic properties in bacterial inactivation. This work presents a design fabrication of low-cost, layered TiO₂ films assembled reactors and a study of ...their performance for a better understanding to elucidate the photocatalytic effect on inactivation of
in water. The ability to reduce the number of bacteria in water samples for the layered TiO₂ composing reactors has been investigated as a function of time, while varying the parameters of light sources, initial concentration of bacteria, and ratios of TiO₂ film area and volume of water. Herein, the layered TiO₂ films have been fabricated on the glass plates by thermal spray coating prior to screen printing, allowing a good adhesion of the films. Surface topology and crystallographic phase of TiO₂ for the screen-printed active layer have been characterized, resulting in the ratio of anatase:rutile being 80:20. Under exposure to sunlight and a given condition employed in this study, the optimized film area:water volume of 1:2.62 has shown a significant ability to reduce the
cells in water samples. The ratio of surface area of photocatalytic active base to volume of water medium is believed to play a predominant role facilitating the cells inactivation. The kinetic rate of inactivation and its behavior are also described in terms of adsorption of reaction species at different contact times.
Titanium dioxide (TiO2) powder was prepared by a sol-gel method. Titanium isopropoxide (Ti(OCH(CH3)2)4) and citric acid
((C3H5O(COO)3)H3·H2O) were used as the starting precursors with a mole ratio of ...1 : 3. Ammonium hydroxide (NH4OH) was
added to adjust the pH of the mixed final solutions. Co-precipitation powder was obtained with the final solutions at pH = 2,
4 and 6. The powder was dried at 80℃ for 24 h and calcined at 400 and 800 ℃ for 2 h with a heating rate of 5 K.minute−1. The
phase transformation was investigated by an X-ray diffractometer (XRD). The anatase structure of titanium dioxide was
obtained after calcination at 400 and 800℃ for 2 h. The microstructure was characterized by a scanning electron microscope
(SEM). The range of particle size was 0.1-0.5 μm with an irregular particle shape. KCI Citation Count: 15
•An ECL-µPAD was made for assessing the amount of trimethylamine in fishes.•The strong ECL signal was enhanced greatly when TGA-capped CdSe-QDs mixed with Ru(bpy)32+ solution.•It involves ECL ...quenching effect measurement by trace concentration of trimethylamine.•The procedure is a sensitive, simple and cost-effective instrument in setup and reliable.•The paper-based sensor is good for food quality monitoring in remote regions and during the transportation.
A paper-based electrochemiluminescence device (µPAD-ECL) for the estimation of trimethylamine (TMA) concentration in fish was developed using tris(2,2ʹ-bipyridyl)ruthenium(II) complex coupled with water soluble thioglycolic acid–capped CdSe quantum dots on the inkjet-printed paper-based device. The quenching effect of tertiary amines on the ECL intensity was found to be sensitive and concentration dependent. This effect allows the measurement of TMA at low concentrations. Under the optimal conditions, the linear concentration range was exhibited from 1 × 10−12 to 1 × 10−7 M and a detection limit of 2.09 × 10−13 M, with relative standard deviation of 1.97 %. The applicability of µPAD-ECL is demonstrated by the rapid estimation of trimethylamine concentration in fish tissue, and could be used as a method for screening the total amount of tertiary amines in fishery products in remote communities. The results obtained using the paper-based devices agreed well with those obtained applying high performance liquid chromatography with benzoyl derivatization, at a confidence level of 95%.
Bismuth titanate powders were synthesised by the oxalate method. Bismuth nitrate pentahydrate and titanium (IV) isopropoxide were used as the starting precursors with a mole ratio of Bi:Ti = 4:3 in ...0.30M oxalic acid medium. The precipitate powders were calcined between 600 and 900 C for 2 h. The structure was studied by XRD, the morphology by SEM, and the elemental composition by EDX. Orthorhombic Bi4Ti3O12 powders were obtained after calcination at 900 C for 2 h. The particles were irregular in shape and highly agglomerated with a particle size ranging from 100-300 nm. The elemental composition of Bi4Ti3O12 powders were identified by the EDX data. 27 refs.
Bismuth titanate (Bi
4Ti
3O
12) fine powders were synthesized from a low temperature hydrothermal method. Bismuth nitrate and titanium isopropoxide were used as the starting materials with the mole ...ratio of Bi:Ti=4:3. Sodium hydroxide was added to adjust the pH of the mixed final solution at 13. The temperature of reaction in the hydrothermal Teflon-lined vessel was 150
°C. The effect of reaction time at 5, 10, and 15
h was investigated. The phase structure was identified by X-ray diffraction (XRD) technique. Orthorhombic structure of Bi
4Ti
3O
12 fine powders was obtained without calcination step. The morphology and microstructure were investigated by scanning electron microscopic (SEM) technique. The powders were generally sphered in shapes and the average sizes were 0.50–1.20
μm.
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•An electrochemiluminescence (ECL) cloth-based analytical device (CAD) is proposed.•The highly sensitive CAD is suitable for the screening of low levels of salbutamol residue in ...pork.•The ECL detection is triggered at a modified platinum nanoparticle-chitosan working electrode.•The CAD is validated with the liquid chromatography–mass spectrometry method and spiked pork samples.
The fabrication of a cloth-based analytical device combined with electrochemiluminescence detection was established for the rapid determination of salbutamol in pork samples. A hand-coloring method to pattern the hydrophobic chamber was employed, and a three-carbon electrode system was subsequently screen printed onto the patterned cotton chamber. Further modifications of the working electrode surface were conducted using platinum nanoparticles and chitosan solution. The salbutamol enhanced the electrochemiluminescence signal of tris(2,2′-bipyridyl)ruthenium(II) complex in the Britton–Robinson buffer of pH 9.5 and the potential quantitative assay for SAL detection was exhibited. The proposed sensor illustrated a linear calibration curve of the logarithmic SAL concentration in the range of 5 × 10−2 to 5 × 104 µg L−1 (r2 > 0.996). A limit of detection of 6.8 ng L−1 was observed. The CAD–ECL sensor was successfully applied for the determination of salbutamol residuals in pork samples. The method validation was performed using the LC-MS method.
This research delves into fabricating a CuO/Fe2O3/ZnO (CFZ) ternary composite photocatalyst, employing grape extract for its eco-conscious synthesis. The method intricately integrates copper acetate, ...ferric nitrate, and zinc acetate as precursor compounds, harmonizing them with grape extract serving as a green reducing agent. Meticulous microwave treatment and controlled calcination orchestrate the nuanced formation of the desired composite material. The extensive characterization, involving X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDXS), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), and photoluminescence (PL) spectroscopy, unveils an array of favorable physical, chemical, and optical attributes conducive to proficient photocatalysis. Notably, CFZ–10mc showcases a narrower bandgap of 1.91 eV, which is pivotal for bolstering electron–hole separation, thereby enhancing its photocatalytic efficacy. Assessment of CFZ's performance in degrading Rhodamine B (RhB) under UV irradiation highlights an impressive 88.8% degradation efficiency within 120 min, accompanied by a kinetic rate constant of 1.81 × 10−2 min−1. Deliberation upon crucial parameters, including photocatalyst dosage, initial RhB pH, and reactor energy consumption, introduces the electrical energy per order (EEO) as a notable efficiency metric. CFZ manifests a substantial reduction in operational costs, estimated to be 18.10 times lower than conventional photolysis, signifying an EEO value of 509.17 kWh m−3 order−1. Optimal operational conditions propose a photocatalyst content of 1.5 g L−1 and an initial RhB pH of 7, fostering the prevalence of the primary active species, •OH. These findings illuminate CFZ's potential in mitigating organic pollutants, underlining its pivotal role in sustainable water remediation. Additionally, practical implementation guidelines for leveraging CFZ's capabilities in real-world applications are presented with care and consideration.
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•CuO/Fe2O3/ZnO created using grape extract, offering an eco–friendly method.•Green synthesis reduces pollutants, showing promise for environmental improvement.•Method's potential in reducing organic pollutants highlighted for environmental benefit.•Advanced photocatalytic oxidation proven cost–effective for toxic pollutant treatment.•Synthesized composite offers hope for pollution reduction, targeting organic contaminants specifically.
Biodiesel has been recognized as the most widely utilized biofuel around the world due to its significant role in reducing the consumption of crude oil and lowering environmental pollution levels. By ...serving as a renewable alternative to fossil fuels, bioethanol helps decrease greenhouse gas emissions and contributes to a more sustainable energy future. Traditionally, alkali hydroxides like NaOH and KOH have been mainstays in biodiesel synthesis. However, their overuse can lead to unwanted byproducts and operational complexities. Since calcium titanate can occur at a strong base condition, it presents an alternative avenue worth exploring. In this study, we investigate the influence of alkali hydroxides, namely LiOH, NaOH, and KOH, on the formation of calcium titanate through hydrothermal methods, with varying heating times. We aim to understand how different hydroxides affect the synthesis process and the resultant properties of calcium titanate. We delve into the vibrational properties of Ca‒O‒Ti and Ti‒O bonds using Fourier transform infrared spectroscopy (FTIR), confirming the presence of calcium titanate (JCPDS No.42-0423) through X-ray diffractometry (XRD). This thorough characterization provides insight into the structural integrity and composition of the synthesized materials. Moreover, scanning electron microscopy (SEM) reveals the intriguing cube-like morphology of calcium titanate, offering visual evidence of its unique structure. The fatty acid methyl ester Iimpressively, our results show that calcium titanate synthesized in 7 M NaOH and KOH solutions, heated for 24 hours, emerges as a promising biodiesel catalyst. We observe fatty acid methyl ester provides the percentages of 63.67% and 90.02%, respectively, indicating the catalytic efficacy of these materials in biodiesel production. These findings not only contribute to the understanding of calcium titanate synthesis but also pave the way for a sustainable future in biodiesel production by introducing efficient and eco-friendly catalysts.
Herein, unloaded WO
3
(WO
3
) and Pt‐loaded WO
3
(Pt‐WO
3
) nanobars are successfully synthesized through simple hydrothermal and impregnation methods. X‐ray diffractometer analysis confirms the ...formation of a monoclinic WO
3
structure. Surface analysis reveals that the Pt impregnation results in a significant increase in the specific surface area of WO
3
nanobars. The gas‐sensing performance of sensors based on nanobars is measured toward ammonia (NH
3
) with varying NH
3
concentrations at different operating temperatures. Compared with the pristine WO
3
sensor, the Pt‐WO
3
‐based sensor with an optimal Pt content of 1 wt% exhibits a relatively low optimum operating temperature of 250 °C and a superior response of 960–50 ppm NH
3
. Furthermore, the Pt‐WO
3
‐based sensor also displays fast response, excellent NH
3
selectivity to ammonia, moderate humidity dependence, and good stability. Therefore, the developed hydrothermal and impregnation methods could be a suitable alternative procedure for the synthesis of Pt‐WO
3
nanobars useful for advanced NH
3
‐sensing applications.
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