JOURNAL OF PHYSICAL CHEMISTRY B
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2015
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IF 3.302
Mei Huang,Shuai He,Wenhong Liu,Yunjin Yao,Shiding Miao
Studies on the configuration of dye molecules are of great importance in revealing origins of the electronic bands as well as understanding their transitions. In this work, we utilized dye molecules named Nile blue A, which are a type of oxazine dyes, to study the molecular configurations when they are transferred from solutions to a solid surface. The Langmuir–Blodgett (LB) technique was employed to construct such an interface where the interaction between the dye molecules and solid supports can be pursued. Hybrid films were prepared via the LB depositions, and the dye molecules were assembled on the elementary clay sheets (laponite, saponite). The configuration of Nb reflected by the molecular orientation, packing density, phase behavior, and variances of the surface tension has been derived. The ex situ spectroscopy characterizations such as UV–vis absorption, fluorescence emission, and excitation spectra were carried out on these LB films to reveal the fact that the adsorbed Nb molecules are mainly assembled in two types of configurations. Adsorbed state I was found to be achieved at high concentrations (1–10 ppm) of clay dispersions and low surface pressure (∼5 mN/m). In this state the anionic oxazine rings of Nb are adsorbed on clay sheets sharing a large lift-off area. This configuration gives allowable fluorescence (λ = 550 nm). Lower clay concentration (<1 ppm) and high surface pressure (10–30 mN/m) yield the adsorbed state II in which the oxazine chromophores were arranged in a side-by-side style, and the dye molecules stand perpendicularly to the clay sheets. This conformation exhibits no photoluminescence.
研究领域:
物理化学
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材料科学
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光谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2022
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IF 5.304
Zhichen Deng,Jiahua Zhang,Zhengquan Su,Yan Bai,Jincan He
Herein, a multi-spectroscopic assay based on a derivatization reaction was proposed for phosphate detection. In this assay, the phosphate with weak spectral signals was transformed to a large ion-association complex via a derivatization reaction. The operation procedure of the assay was easily performed by physically mixing sulfuric acid, derivatization reagent, phosphate (or sample solution), and dye probe (Nile blue A) for 10 min. Considerable changes in three types of spectral signals, i.e., resonance Rayleigh scattering (RRS), fluorescence, and ultraviolet-visible absorption, could be achieved. Under certain conditions, good linear relationship was obtained between each of the three signal variations and the phosphate concentration. The assay shows good selectivity and high sensitivity with limits of detection (LOD) of 4.8, 4.9 and 5.2 ng/mL for the RRS method, fluorophotometry and spectrophotometry, respectively. The multi-spectroscopic assay was applied to detect phosphate in real food samples, achieving recoveries of 93.3 %–109.6 % and relative standard divisions of 1.8 %–7.1 %. Owing to its speediness, easy operation, high sensitivity, good selectivity, self-comparison function, the multi-spectroscopic assay exhibits great potential for determination of phosphate in complex samples and provides an instructive strategy for detecting analytes with no or weak spectral signal.
研究领域:
分析化学
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食品科学
✓ 已验证
DOI
高影响因子
NANO
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2018
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IF 1.1
Chang Liu,Qianqian Su,Li Li,Jie Sun,Jian Dong,Weiping Qian
In this work, we designed a simple substrate-immersed solvothermal route for the one-step synthesis of novel ordered SiO 2 /Ag arrays, employing SiO 2 colloidal crystals as templates and alcohol as reducing agent. The Ag nanoparticles were uniformly deposited in situ onto SiO 2 colloidal crystals, which exhibited high surface enhanced Raman spectroscopy (SERS) activity and uniform SERS intensity. It was found that ordered SiO 2 /Ag arrays could rapidly scavenge the absorbed-Nile blue A (NBA) molecules from the surfaces with the assistance of H 2 O 2 , while the SERS signals of NBA decreased sharply and almost completely disappeared within four minutes. This can be attributed to the superior catalytic activity of Ag nanoparticles. After five times of re-immersion and re-absorbing process of NBA, the substrates could still keep ∼ 74.8% SERS intensity versus the original. The high activity and durability of the as-prepared SiO 2 /Ag SERS substrate endow them as a promising candidate for trace detection.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
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2023
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IF 6.1
Nuo Duan,Yuting Chang,Wenhui Lv,Changxin Li,Chunxia Lu,Zhouping Wang,Shijia Wu
Herein, a SiO 2 @Ag NPs core/shell nanoparticles were synthesized to fabricate a surface-enhanced Raman spectroscopy (SERS) sensor for the simultaneous determination of histamine (HIS) and tyramine (TYR) based on specific aptamer recognition and ratiometric strategy. SiO 2 @Ag NPs with 4-thiosaminophenol (4-ATP) and Nile blue A (NBA) molecules were used as an internal standard (IS) and labeled with aptamers corresponding to HIS and TYR, respectively. Raman reporter molecules ROX and Cy5 labeled complementary DNA (cDNA) were then hybridized with aptamers to form rigid double-stranded DNA. After the HIS and TYR were captured by their aptamers, resulting in the dissociation of cDNA and separated from the SERS substrate. Therefore, the SERS signal intensity at 1503 cm −1 of ROX and 1358 cm −1 of Cy5 tagged on the terminal of cDNA decreased with the concentration of HIS and TYR increasing, while the SERS signal intensity at 1079 cm −1 of 4-APT and 592 cm −1 of NBA on the substrate remain stable. Thus, the concentrations of HIS and TYR can be determined by the I 1503 /I 1079 and I 1358 /I 592 values, respectively. This sensing strategy achieves a lower detection limit of 0.2 ng/mL for HIS and 0.05 ng/mL for TYR, respectively, demonstrating promising applications in sensitive detection of BAs in animal-derived foodstuff.
研究领域:
分析化学
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食品科学
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生物技术
✓ 已验证
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）