POLYMER
·
2024
·
IF 4.1
Zhisong Li,Linbo Wu
Poly(ethylene furandicarboxylate) (PEF) is prone to discolor and its color is an important quality index. However, in the case of crystalline PEF, its chromatic values (CVs) measured by colorimeter are underestimated significantly due to whitening caused by crystallization and thus does not reflect its true/intrinsic color correctly. In this study, the CIELAB CVs ( L *, a * and b *) and UV–vis spectra of 35 amorphous PEF samples were measured. A new comprehensive CV (Δ E 6 ) is defined from CIELAB CVs and used to characterize the color of PEF. A quaternary power function model between Δ E 6 and integrals of absorbance of PEF solution in yellow, red, blue and green visible sub-regions is established. Δ E 6 agrees well with those calculated from absorbance integrals. As the absorbance measurement is convenient and not affected by crystallization, this model can be used to measure real/intrinsic color of crystalline PEF as well as amorphous one.
研究领域:
材料科学
·
分析化学
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产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Rong Zhao,Qiang Niu,Ghulam Murtaza,Guling Zhang,Yuping Yang
The accurate detection of dehydration processes in hydrated drugs can reveal various intermolecular vibration modes mediated by hydrogen bonds between water molecules and other components, which underpin the further development of pharmaceutical science, food safety and biophysics. Herein, terahertz (THz) technology is utilized to investigate the dehydration state of d (+)-Raffinose pentahydrate (Rf·5H 2 O), in conjunction with imaging-based point by point scanning data acquisition and barcodes methods, to establish an innovative platform integrated identification, trace detection, and application capabilities. Our study demonstrates that the dehydration process of Rf·5H 2 O can be dynamically monitored through the evolution of its THz absorption peaks, offering more precise results compared to XRD and Raman spectroscopies. Moreover, the absorbance spectra data collected at each individual pixel is utilized to build visualized THz images, achieving an ultralow minimum content required for detection of 0.032 μg/(50 μm) 2 . Additionally, we introduce a THz spectra-barcode conversion system that not only ensures efficient electronic recordkeeping but also enhances user readability, thereby facilitating the practical applications of THz technology.
研究领域:
药学
·
食品科学
·
生物物理学
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产品关联
DOI
PubMed
高影响因子
POWDER TECHNOLOGY
·
2020
·
IF 4.142
Jinwei Song,Weixue Jiang,Hua Qian,Kai Du
Different mass concentrations of ammonia-water TiO 2 nanofluids are applied to AARS and undergo the alternating pressure and temperature conditions. Applied nanofluids are periodically sampled and the absorbance, thermal conductivity , viscosity and surface tension of them are measured. So that the influence of the alternating working conditions on the nanofluid properties can be figured out. Experimental results show that the absorbance of the nanofluids circling in solution cycle is still gradually decreased over time, but the absorbance declining rates of them are much slower than that of nanofluids resting outside the system (the absorbance of the circulated nanofluids is about 3.5 times than that of resting nanofluid after 140 h); the changes of the thermal conductivity and viscosity of the nanofluids are highly correlated with the change of the absorbance of the nanofluids; the surface tension is significantly reduced after the addition of the surfactant at the same mass concentration.
研究领域:
热力学
·
材料科学
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Bingya Chen,Chenyang Zhang,Yanmei Zhao,Dongsheng Wang,Gregory V. Korshin,Jinren Ni,Mingquan Yan
This study compared chlorination-induced changes of the properties of natural organic matter (NOM) represented by standard humic substances and NOM present in pristine and anthropogenically-affect reservoirs, rivers, groundwater and seawater. The chlorination-induced changes of NOM properties were quantified using the differential absorbance spectra (DAS) which were processed via numeric deconvolution . Six Gaussian bands were found to comprise the DAS of all examined waters. These bands (denoted as A0, A1, A2, A3, A4 and A5, respectively) have maxima located at ca. 200, 240, 276, 316, 385 and 547 nm. The bands A1-A4 were observed in the DAS of representative model chlorinated compounds. Quantum chemical (QC) calculations were carried out to examine the intrinsic nature of these bands and electronic transitions associated with them. QC data demonstrate that bands A1 and A2 are present in almost all aromatic organic species, A3 is likely to be associated with acetophenone- and/or styrene-like groups. A4 can be attributed to the engagement of m-hydroxyaromatic and flavone-type groups typical for the polyphenolic moiety in NOM and known to be the key precursors of disinfection by-product (DBP) formation. Thus, the intensity of band A4 is predicted to be an especially strong predictor of DBP formation.
研究领域:
环境科学
·
化学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Wen Qin,Jianshan Peng,Jingru Yang,Yang Song,Jun Ma
In this study, the relative residual UV absorbance (UV 254 ) and/or electron donating capacity (EDC) was investigated as a surrogate parameter to evaluate the abatement of micropollutants during the Fe(II)/PMS and Mn(II)/NTA/PMS processes. In the Fe(II)/PMS process, due to the generation of SO 4 •- and •OH at acidic pH, UV 254 and EDC abatement was greater at pH 5. In the Mn(II)/NTA/PMS process, UV 254 abatement was greater at pH 7 and 9, while EDC abatement was greater at pH 5 and 7. This was attributed to the fact that MnO 2 was formed at alkaline pH to remove UV 254 by coagulation, and manganese intermediates (Mn(V)) were formed at acidic pH to remove EDC via electron transfer . Due to the strong oxidation capacity of SO 4 •- , •OH and Mn(V), the abatement of micropollutants increased with increasing dosages of oxidant in different waters in both processes. In the Fe(II)/PMS and Mn(II)/NTA/PMS processes, except for nitrobenzene (∼23% and 40%, respectively), the removal of other micropollutants was greater than 70% when the oxidant dosages were greater in different waters. The linear relationship between the relative residual UV 254 , EDC and the removal of micropollutants was established in different waters, showing a one-phase or two-phase linear relationship. The differences of the slopes for one-phase linear correlation in the Fe(II)/PMS process (micropollutant-UV 254 : 0.36–2.89, micropollutant-EDC: 0.26–1.75) were less than that in the Mn(II)/NTA/PMS process (micropollutant-UV 254 : 0.40–13.16, micropollutant-EDC: 0.51–8.39). Overall, these results suggest that the relative residual UV 254 and EDC could truly reflect the removal of micropollutants during the Fe(II)/PMS and Mn(II)/NTA/PMS processes.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2013
·
IF 3.532
Zhidan Tian,Baozhu Tian,Jinlong Zhang
Two new rhodamine dyes (Rh Q-H, Rh Q-Me) containing 1, 4-diethyl-1, 2, 3, 4-tetrahydroquinoxaline as an effective electron donor are designed and synthesized. The structures of the novel compounds are confirmed by 1 H NMR, 13 C NMR and ESI . Due to an excited-state intramolecular charge transfer (ICT), the new dyes exhibit longer absorption (>580 nm) and emission (>640 nm) compared with the model compounds, rhodamine 101 and rhodamine 6G. The new rhodamine dyes show large Stokes shift of 40–50 nm in commonly used solvents. Notably, when measured in a mixture of H 2 O/EtOH solution, significant stokes shift of 65–68 nm are achieved, which is among the largest Stokes shifts ever reported for rhodamine dyes.
研究领域:
有机化学
·
材料科学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 9
·1-9
·
IF 6.232
Hu Xuemei,Wei Zixuan,Tang Menghuan,Long Yijuan,Zheng Huzhi
Lowering the background signal for more sensitive analysis of determinands is as important as amplifying the target signal. The photoinduced oxidase of fluorescein has been reported, which can catalyze the oxidization of common substrates in a few minutes. As a metaphor for locks and keys, we designed double locks confining the activity of fluorescein to reduce the background absorbance during colorimetric detection. The first lock inhibits the main activity of fluorescein by phosphating. The second lock almost completely deactivates fluorescein by forming coordination nanoparticles (CNPs) via the self-assembly of cerium chloride and fluorescein diphosphate (FDP). The Ce-FDP CNPs are characterized by scanning electron microscope (SEM), dynamic light scattering (DLS), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectrum (EDS), which show electrostatic formation and amorphous character in the morphology. Alkaline phosphatase (ALP), the key to release fluorescein, can destroy Ce-FDP CNPs along with decomposing FDP by degrading phosphate groups. Therefore, a novel colorimetric strategy for sensitive detection of ALP is established. The detection of α-fetoprotein (AFP) is further succeeded by labeling AFP antibody with ALP. By dramatically reducing the background absorbance, the detection limits of ALP and AFP are as low as 0.014 mU/mL and 0.023 ng/mL, respectively. This convenient, brief, sensitive assay provides a promising prospect for clinical diagnosis.
Graphical abstract
研究领域:
分析化学
·
生物传感器
·
临床诊断
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Jiangru Wang,Qirui Shen,Xifeng Yu,Qi Kang,Dazhong Shen
Multi-signal assays offer the advantage to improve the accuracy and diversity by integrating the merits of each output. In the widely used colorimetric and fluorometric dual-mode, the fluorescent intensity and absorbance signals are usually measured by a lab spectrofluorometer and a spectrophotometer. Herein, a smartphone-based device which is able to measure simultaneously the ratiometric fluorescence and absorbance signals was designed. Its analytical performance is demonstrated by the determination of Rhodamine B (Rh B). In a three-channel cuvette, the detection cell (with test solution) was sandwiched between two light intensity measurement cells (with Rh B standard solution). Under the irradiation of the excitation light of 550 nm, the fluorescent images of the three cells were captured by the camera in a smartphone. The ratiometric fluorescence at 590 nm and the absorbance at 550 nm are obtained according to the brightness ratio of the middle cell and the third cell to the first one, respectively. The dual-mode of fluorescence and absorbance can widen the detection range, with the limit of detection for Rh B of 3.2 nM in ratiometric fluorescence mode and 0.38 μM in absorbance outputs, respectively. Importantly, the possible inner filter effect at the excitation wavelength of the fluorescence can be corrected according to the absorbance signal, improving the accuracy of determination. The dual-mode portable device was used to determine Rh B in combination with differential molecularly imprinting strategy to improve further the anti-interference ability.
研究领域:
分析化学
·
光谱学
·
光学传感
·
环境监测
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Bei Ye,Wen-Long Wang,Chen-Xin Xu,Wei Wang,Min-Yong Lee,Shu-Yan Zhan,Qian-Yuan Wu
Microbubble aeration can greatly improve ozonation by enhancing ozone transfer and subsequent hydroxyl radical formation. Here, we applied microbubble ozonation to treat pharmaceuticals and personal care products (PPCPs) in several municipal secondary effluents. Compared with conventional ozonation, microbubble ozonation efficiently eliminated both ozone-reactive and ozone-resistant PPCPs and greatly reduced the ozone doses in the complex water matrixes of the secondary effluents. In addition, compared with millibubble ozonation, the removal of chemical oxygen demand (COD) increased by 32.0 %–67.2 % at 60 mg/L ozone dose during microbubble ozonation. The carbon emission of microbubble ozonation varied in different water matrix, and was 47–76 % less than that of millibubble ozonation. The oxidizing capacity ratio of microbubble to millibubble for PPCPs was between 1.26 and 3.50 times, and ozone-resistant PPCPs removal was enhanced more than ozone-reactive PPCPs by microbubble ozonation. Specifically, the oxidizing capacity ratio of microbubble to millibubble for carbamazepine (ozone-reactive) was 1.30–2.43 times, whereas that for N,N -diethyl-3-tolumide (ozone-resistant) was 1.88–3.50 times. Microbubble ozonation also greatly decreased the UV absorbance and fluorescence for all of the water samples. The UV absorbance at 254, 280, and 320 nm decreased by 64.0 %–83.8 %, and the fluorescence peak intensity decreased by more than 94 %. Surrogates for the removal of PPCPs and COD were evaluated and compared. This study provides new insights into the application of microbubble ozonation to control PPCPs in secondary effluents.
研究领域:
环境工程
·
水处理
·
化学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2018
·Vol. 6
·期 42
·6858-6864
·
IF 4.776
Wenying Li,Jiayan Wang,Jiacheng Zhu,Yue-Qing Zheng
Nanomaterial-based artificial enzymes (nanozymes), as an emerging generation of artificial enzymes, have received extensive attention in recent years owing to their striking merits. In this study, the obtained Co3O4 nanocrystals exhibited catalase-like activity and could catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2, and a clear absorption peak at 652 nm can be observed. It was verified that the catalytic activity for the oxidation of TMB originated from the oxygen, which is generated by Co3O4 catalyzed H2O2 decomposition. Upon addition of glutathione (GSH), the catalytic ability of the Co3O4 nanocrystals was inhibited. And, the changes of absorbance at 652 nm could be utilized to quantify the concentration of GSH. Under the optimized conditions, the proposed assay showed good linear relationships and a low detection limit towards GSH. Moreover, the Co3O4 nanocrystals had excellent stability and can maintain the catalytic activity for a long time. Thus, a simple, sensitive and selective nanozyme-based biosensor was developed for the colorimetric detection of GSH.
研究领域:
纳米技术
·
分析化学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2014
·
IF 3.511
Jinglei Yuan,Shijia Wu,Nuo Duan,Xiaoyuan Ma,Yu Xia,Jie Chen,Zhansheng Ding,Zhouping Wang
In this study, a gold nanoparticle-based colorimetric aptasensor for Staphylococcus aureus ( S. aureus ) using tyramine signal amplification (TSA) technology has been developed. First, the biotinylated aptamer specific for S. aureus was immobilized on the surface of the wells of the microtiter plate via biotin–avidin binding. Then, the target bacteria ( S. aureus ), biotinylated-aptamer–streptavidin-HRP conjugates, biotinylated tyramine, hydrogen peroxide and avidin–catalase were successively introduced into the wells of the microtiter plate. After that, the existing catalase consumed the hydrogen peroxide. Finally, the freshly prepared gold (III) chloride trihydrate was added, the color of the reaction production would be changed and the absorbance at 550 nm could be measured with a plate reader. Under optimized conditions, there was a linear relationship between the absorbance at 550 nm and the concentration of S. aureus over the range from 10 to 10 6 cfu mL −1 (with an R ² of 0.9947). The limit of the developed method was determined to be 9 cfu mL −1 .
研究领域:
生物技术
·
分析化学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Liubing Kong,Ying Gan,Tianxing Wang,Xianyou Sun,Chiyu Ma,Xinyi Wang,Hao Wan,Ping Wang
Okadaic acid (OA), one of the most widely distributed marine toxins worldwide poses a severe threat to human health. Previous sensing methods for OA detection are usually based on antigen-antibody binding mechanism. However, the drawbacks of antibodies especially the enzyme-labeled antibodies, such as the harsh storage condition and high cost, lead to significant challenges to OA detection in biological samples. To overcome these limitations, a single-stranded DNA binding protein (SSB) coupled aptasensor was developed for OA detection. SSB was incubated on the microplate as a substitute for conventional OA-protein conjugations. Carbon-gold nanoparticles were synthesized and labeled with horseradish peroxidase and thiol-modified aptamers to obtain a capture probe ( [email protected] ) instead of the enzyme-labeled antibody for signal amplification. OA and SSB competed to bind with limited aptamers on [email protected] probes followed by colorimetric assay to obtain the optical signals correlated to OA concentration. To achieve on-site detection, a miniaturized and multichannel absorbance reader (Smart-plate reader) was self-designed with full automation for OA detection. Utilizing the SSB coupled aptasensor and the Smart-plate reader, our approach enables cost-effective and on-site OA sensing with a detection range of 2.5–80 ppb and an ultra-low limit of detection of 0.68 ppb. Moreover, novel OA detection kits based on the SSB coupled aptasensor were prepared which can effectively reduce the cost by 15 times lower than that of commercial ELISA kits. Therefore, the developed platform provides a favorable and promising avenue for marine toxin detection in aquaculture and food safety.
研究领域:
生物技术
·
环境科学
·
分析化学
·
食品安全
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）