MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Shilan A. Fatah,Khalid M. Omer
Ofloxacin (OFL), a broad-spectrum fluoroquinolone antibiotic, is widely utilized for treating bacterial infections. Accurate detection of OFL is essential for pharmaceutical quality control and environmental monitoring, particularly in wastewater. This study introduces a novel fluorescence-based detection method using sumac-derived carbon dots (S-CDs), synthesized via a simple hydrothermal approach. The S-CDs exhibited spherical morphology (20–30 nm) with blue fluorescence emission and a quantum yield of 1.4 %. Upon interaction with OFL, a remarkable fluorescence enhancement was observed, resulting in a 45-fold increase in quantum yield (45.0 %) accompanied by a red shift in the emission. This strong enhancement and red-shift emission enabled to design off–on mode for detection of OFL. The fluorescence intensity showed a strong linear correlation with OFL concentration (R 2 = 0.98) in the range of 1–90 nM, with a limit of detection (LOD) of 0.7 nM and a limit of quantification of 2.3 nM. Furthermore, a smartphone-assisted visual detection method was developed based on an off–on fluorescence mechanism. RGB analysis enabled real-time quantification of OFL, exhibiting a linear detection range of 20–80 µM with an LOD 0.97 µM. The method was successfully applied to detect OFL in eye drop formulations and tap water, demonstrating high accuracy and precision. These findings underscore the potential of S-CDs as a cost-effective, portable, and efficient tool for OFL detection, suitable for pharmaceutical and environmental monitoring applications.
研究领域:
环境科学
·
分析化学
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产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 9
·5478-5485
·
IF 1.134
Xie Cong,Zhao Yubin,Song Yuxiang,Liu Yingjie,Wang Yaya,Yang Ping
Compared with conventional semiconductor quantum dots, hybrid SiO2 coated CdTe QDs exhibited high stability, long fluorescent lifetime, high photoluminescence quantum yields, and well biocompatibility. In this paper, CdTe QDs with tunable PL from green to red emitting were
prepared by an aqueous synthesis. A sol–gel process resulted in CdTe QDs coated with a hybrid SiO2 shell contained CdS-like clusters to obtain red-shifted PL spectra, increased PL efficiency and high stability. The clusters were formed by the reaction of Cd2+ and
S2− ions generated via the decomposition of thioglycolic acid. The clusters around CdTe cores created a core–shell structure which is very similar with traditional semiconductor core–shell QDs. After being coated with a hybrid SiO2 shell, the PL of green-emitting
naked CdTe QDs was red-shifted largely (~30 nm) while the PL of yellowemitting CdTe QDs revealed a small red-shifted (~20 nm). Furthermore, The PL of red-emitting naked CdTe QDs was red-shifted much small (less than 10 nm). This phenomenon is ascribed to the change of band gap of CdTe cores
with sizes. The red-shift of PL spectra is attributed to the CdS-like clusters around the core rather than the thickness of the hybrid SiO2 shell.
研究领域:
材料科学
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纳米技术
·
光学
✓ 已验证
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Angxin Tong,Xiaojun Tang,Feng Zhang,Bin Wang
In this study, we mainly focused on predictable regularities of the red shift of ultraviolet spectra for β-phenylethylamine (PEA), NaCl and NaOH in aqueous solution. The absorption peaks of the UV spectra near 191 nm of NaCl, NaOH and PEA in aqueous solution moved in the direction of a red shift while the molar absorption coefficient at the peak increased regularly with the increasing solution concentration. These shifts were obtained for solutions with concentrations ranging from 3.68 to 1000 mmol/L for NaCl, from 0.762 to 2000 mmol/L for NaOH, and from 0.0515 to 8.91 mmol/L for PEA. The plots of the logarithm of the solution concentration for NaCl and PEA versus the absorbance at 191 nm and at the peak were linear, and the plots of the logarithm of the solution concentration for NaCl and PEA versus the wavelength at the peak (shifted from 191 nm) were also linear. In addition, the plots of the logarithm of the solution concentration for NaOH that ranged from 0.762 to 1.96 mmol/L versus the absorbance at 191 nm and at the peak were linear as well as the plots of the logarithm of the solution concentration for NaOH that ranged from 1.96 to 2000 mmol/L versus the wavelength at the peak. The slopes of the absorbance at 191 nm of PEA, NaCl and NaOH were somewhat similar to the absorbance at the peak separately, whereas the slopes of the wavelengths at the peak were different from them. Finally, in order to obtain the predictable regularity of the red shift of the UV spectrum for the mixture, 22 ternary mixtures were prepared. The results indicate that the inhibiting effect of hydroxide ions (OH-) caused the wavelength near 206 nm to remain unchanged when the solution concentration of NaOH in the mixture was more than 0.762 mmol/L.
研究领域:
化学
·
光谱学
·
分析化学
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-7
·
IF 4.259
Liu Jian,Bi Hong,Cesar Morais Paulo,Zhang Xiang,Zhang Fapei,Hu Lin
Room temperature magnetic ordering is reported for very small carbon dots (CDs), mat-like polyaniline nanofibers (Mat-PANI) and a composite of CDs@Mat-PANI containing 0.315 wt% CDs. We have found saturation magnetization ( M
S
) of CDs, Mat-PANI and CDs@Mat-PANI at 5 (20/300) K equals to 0.0079 (0.0048/0.0019), 0.0116 (0.0065/0.0055) and 0.0349 (0.0085/0.0077) emu/g, respectively. The M
S
enhancement in CDs@Mat-PANI (200% and 40% at 5 K and 300 K, respectively) is attributed to electron transfer from Mat-PANI imine N-atoms to the encapsulated CDs. Changes in M
S
values reveal that 0.81 (0.08) electron/CD is transferred at 5 (300) K, which is supported by observation of CDs photoluminescence (PL) redshift while in CDs@Mat-PANI. Band-bending and bandgap-renormalization calculations are used to predict a redshift of 117 meV at 300 K as a result of the electron transfer, in excellent agreement with the PL data (110 meV). Raman, X-ray diffraction and X-ray photoelectron spectroscopy data are used to confirm the electron transfer process as well as the strong interaction of CDs with PANI within CDs@Mat-PANI, which increases the crystalline domain size of Mat-PANI from about 4.8 nm to 9.2 nm while reducing the tensile strain from about 6.2% to 1.8%.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Science of Advanced Materials
·
2019
·Vol. 11
·期 1
·105-111
·
IF 1.158
Di Huang,Long Yanju,Luo Lijun,Li Lingxin,Zhang Sifeng,Wang Lulu,Jiang Fengzhi
N-doped Bi2O3 with hierarchical structure was synthesized using precipitation/calcination method. In this method, ethylenediamine was used as both the nitrogen source and morphology controller besides the P123 triblock copolymer as main structure directing agent,
to control the texture and morphology of the catalyst. The microstructure and chemical composition of N-doped Bi2O3 photocatalyst were characterized with XRD, XPS, SEM-EDS, DR UV-vis, and N2 physisorption. The prepared hierarchical N-doped Bi2O3
was used for the photocatalytic degradation of 17β-estradiol (E2) under visible light. The absorption edge of prepared N doped Bi2O3 appeared an obvious red shift comparing with pure phase Bi2O3. This would help photocatalyst make full
use of light source to degrade E2. Under the same conditions of the photocatalytic reaction, the rate constant of degradation of E2 over N-doped Bi2O3 was 6.3 times of that obtained over Bi2O3. The stability of N-doped Bi2O3
and the mechanism of the photocatalytic degradation of E2 under visible light were studied.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Wanrong Zou,Jiurong Li,Xiao Gong
This paper presents a straightforward synthesis strategy for N, S co-doped carbon nanodots (N, S-CDs), aiming to achieve CDs emitting ultra-wide redshifts while obtaining excellent metal ion detection performance. The N, S-CDs display excellent fluorescence (FL) emission independence regardless of the excitation wavelength or concentration. By introducing a single dopant thiourea, the FL emission of CDs was red-shifted from 445 to 575 nm (∼130 nm). The doped N and S elements are discovered to cause the introduction of defective energy levels and an elevation in oxidation on the surface of CDs, which could potentially be the crucial factor for the ultra-wide redshift of FL emission. Also, it is investigated that solvent engineering is essential for the redshift of the emission peak, which can also be an effective way to synthesize multicolor CDs. Furthermore, the N, S-CDs can be utilized for measuring the water content in methanol solvent based on their solvent effects. Additionally, N, S-CDs have the capability of detecting Mn 2+ with high selectivity and sensitivity. The interaction of CDs with Mn 2+ resulted in an obvious change in both the UV absorption spectrum and FL lifetime. To put it differently, the reaction mechanism between CDs and Mn 2+ probably includes mixed processes of dynamic and static quenching. Zeta potential tests additionally indicate that the FL quenching is strongly correlated with the surface condition of CDs. The outcomes and discoveries offer a fresh and viable method for achieving the simultaneous production of long-wavelength glowing CDs and their analysis and detection of metal ions as fluorescent probes.
研究领域:
材料科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Teng Zheng,Laihui Luo,Peng Du,Stefan Lis,Ulises R Rodríguez-Mendoza,Víctor Lavín,Inocencio R. Martín,Marcin Runowski
To overcome the challenges of pressure monitoring with high sensitivity, we have designed a series of Ce 3+ -activated Ca 2 Gd 8 Si 6 O 26 phosphors with outstanding pressure sensing properties. Excited with UV light, the resultant phosphors can emit a blue-violet luminescence, originating from optically active Ce 3+ ions. The optimal doping content for Ce 3+ ions in the Ca 2 Gd 8 Si 6 O 26 host lattices is 3 mol%, for which the concentration quenching mechanism is dominated by the electric dipole–dipole interaction. The thermal stability of the prepared phosphors was explored by measuring temperature-dependent emission spectra, and determining the activation energy, which is ∼ 0.225 eV. Furthermore, in order to study the pressure sensing ability of the designed phosphors, their luminescence spectra were recorded as a function of pressure up to ∼ 10 GPa. With increasing pressure, an abnormal enhancement of emission intensity was observed, with an enormous red-shift of the emission band of 3.00 nm/GPa, and a decreasing full width at half maximum (FWHM) of − 2.45 nm/GPa for the synthesized phosphors. The determined performance of the sensors developed now classifies them as the most sensitive pressure gauges, i.e., the shift rate is approximately one order of magnitude higher than that of the commonly used ruby sensor. Importantly, the developed pressure sensor shows a negligible temperature dependence, i.e., 0.0023 nm/K for the line-shift and 0.0017 nm/K for the FWHM, and an ultrafast response due to the short emission lifetime of the Ce 3+ excited state of ∼ 20 ns. Additionally, the structural stability of the compounds under pressure is verified by Raman spectroscopy up to ∼ 11 GPa. These results make the Ce 3+ -activated Ca 2 Gd 8 Si 6 O 26 phosphors a promising candidate for ultrasensitive manometry and provide some guidelines for the development of novel pressure sensors.
研究领域:
材料科学
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光学
·
物理学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Zhanglin Chen,Songmo Du,Fei Li,Shijia Zhang,Shuo Zhao,Zhaobo Tian,Jie Zhang,Xuanyi Yuan,Guanghua Liu,Kexin Chen
Photoluminescent materials, serving as optical probes, constitute a significant medium for reliable remote sensing of fundamental state parameters such as temperature and pressure. Herein, we report a novel Mn 4+ -activated perovskite-type La 3 Mg 2 SbO 9 phosphor (LMS:Mn 4+ ) for bifunctional application in both thermometry and manometry. Upon excitation with 341 nm, LMS:Mn 4+ (0.7% Mn 4+ ) emits a bright narrow-band red light peaking at 705 nm with an FWHM (full width at half maximum) of 32 nm. As a thermometer, when the temperature surpasses 298 K, non-radiative transitions from the 2 E g excited state lead to a sharp decrease in decay lifetimes with increasing temperature. This allows for lifetime-based luminescence thermometry with a relative sensitivity of 2.52% K −1 at 391 K. Moreover, LMS:Mn 4+ was processed into a temperature-sensing coating and its non-contact thermometry functionality was validated. In manometry applications, the LMS:Mn 4+ probe experiences substantial pressure-dependent redshift with a sensitivity of 1.20 nm/GPa in the testing range of 9.48 GPa, which is about 3.3 times that of conventional ruby probes. Furthermore, its FWHM consistently remains below 37 nm, which contributes to a high reliability of pressure measurements. The above results indicate that the LMS:Mn 4+ constitutes a promising bifunctional luminescence probe material in thermometry and manometry.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 10
·2377
·
IF 4.2
Zhilei Wang,Zipeng Zhang,Chenyu Wu,Zikuan Wang,Wenjian Liu
The photocatalyst (PC) zinc tetraphenylporphyrin (ZnTPP) is highly efficient for photoinduced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. However, ZnTPP suffers from poor absorbance of orange light by the so-called Q-band of the absorption spectrum (maximum absorption wavelengthλmax= 600 nm, at which molar extinction coefficientεmax=1.0×104L/(mol·cm)), hindering photo-curing applications that entail long light penetration paths. Over the past decade, there has not been any competing candidate in terms of efficiency, despite a myriad of efforts in PC design. By theoretical evaluation, here we rationally introduce a peripheral benzo moiety on each of the pyrrole rings of ZnTPP, giving zinc tetraphenyl tetrabenzoporphyrin (ZnTPTBP). This modification not only enlarges the conjugation length of the system, but also alters thea1uoccupiedπmolecular orbital energy level and breaks the accidental degeneracy between thea1uanda2uorbitals, which is responsible for the low absorption intensity of the Q-band. As a consequence, not only is there a pronounced hyperchromic and bathochromic effect (λmax= 655 nm andεmax=5.2×104L/(mol·cm)) of the Q-band, but the hyperchromic effect is achieved without increasing the intensity of the less useful, low wavelength absorption peaks of the PC. Remarkably, this strong 655 nm absorption takes advantage of deep-red (650–700 nm) light, a major component of solar light exhibiting good atmosphere penetration, exploited by the natural PC chlorophyll a as well. Compared with ZnTPP, ZnTPTBP displayed a 49% increase in PET-RAFT polymerization rate with good control, marking a significant leap in the area of photo-controlled polymerization.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Jun-Ru Tian,Jie-Yao Song,Zhongchang Wang
Conventional fluorescent pH sensors, despite offering high sensitivity and rapid response, are limited by their reliance on fluorescence intensity changes, hindering applications requiring precise wavelength control. Here, we present a pH sensing strategy based on cross-linked carbon quantum dots (CCL-CQDs) displaying a remarkable pH-dependent red shift in the fluorescence emission wavelength. Amino- and carboxyl-functionalized CQDs were synthesized via a one-step hydrothermal method and further assembled into CCL-CQDs through the condensation reaction between amino groups and glutaraldehyde. The CCL-CQDs displayed excellent pH sensitivity, with their fluorescence emission wavelength exhibiting a linear red shift upon increasing pH (from 2.29 to 7.16). The results of mechanism exploration revealed that H+ induced the cleavage of C═N bonds in the CCL-CQD structure, leading to the formation of –COOH groups and increased surface-oxidized carbon content. This enhanced oxidation generated more surface defects, triggering a wavelength shift in surface-state-related fluorescence emission. This study demonstrates the successful synthesis of pH-sensitive CCL-CQDs with an excellent fluorescence detection performance.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Hong Zhu,Zhichao Liu,Chenbo Xu,Caiqi Chen,Jinxuan Wen,Keqin Yang,Suqin Chen,Yuexiao Pan
With unique electronic and optical properties , the size and luminescence color of metal halide perovskite nanocrystals CsPbBr 3 (CPB) are crucial for the potential applications including solid-state lighting, photovoltaics , and thermoelectrics . In this work, we have developed a viable design strategy toward cubic CPB nanoplatelet (NPs) with blue emission at 450–467 nm and a large red shift to the green region at 500–512 nm occurs through a cooperative effect of the ligands 4 -bromo-butyric acid (BBA) and oleylamine (OLA). The influence of the molecular ratio of BBA/OLA, reaction time and temperature on the transformation from blue to green has been investigated systematically. The red shift in the PL of CPB NPs is ascribed to the growth of the crystals with decreased quantum confinement. The photoluminescence quantum yields (PLQYs) of the blue and green luminescence of the obtained CPB NPs reach 94.4 % and 84.4 %, respectively. This proposed strategy not only experimentally fabricates size-adjustable CPB NPs but also helps to reveal in depth the mechanisms of the large variation of quantum confinement in pure cubic CPB NPs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2023
·
IF 8.6
Yu Chen,Zhiyu Yang,Jiance Jin,Jianwei Qiao,Yuzhen Wang,Maxim S. Molokeev,Hendrik C. Swart,Zhiguo Xia
Exploring oxide-based red-emitting phosphors is essential for improving the color rendering index (Ra) and reducing the correlated color temperature (CCT) of white-light-emitting diode (LED) lighting sources. Especially, it is challenging to design Eu2+ red emission in inorganic solids. Here, the Eu2+-activated oxide phosphor Sr2LaGaO5:Eu2+ was synthesized with red emission peaking at 618 nm under 450 nm excitation. The crystal structure and spectral analysis indicate that Eu2+ tends to occupy [Sr1/LaO8] polyhedrons with a smaller coordination number, resulting in a large crystal field splitting at the 5d level and realizing the broadband 4f–5d red emission. When Sr is substituted by Ba atoms, density functional theory calculations verify that Ba tends to enter [Sr2O10] with a large coordination number, further giving rise to the lattice distortion and a giant spectral redshift (618–800 nm). The white LED device fabricated by mixing red Sr1.8Ba0.2GaO5:Eu2+ and green Lu3Al5O12:Ce3+ phosphors exhibits a high color rendering index (Ra = 92.1) and a low color-dependent temperature (CCT = 4570 K). This study will give guidance for exploring new Eu2+ activated oxide-based red phosphors as well as achieving tunable emission through cations’ substitution.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
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