MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Jing Liu,Chao Dou,Wei Chen,Han Yan,Wen-Zhuang Ma,Dan Meng,Xue-Qiu You,Yu-Shan Chen,Changjie Zhou,Pingping Zhuang
Nitrate anions are the main form of nitrogen in the environment and threaten the ecosystem and human health when their concentration is beyond 0.3 mg L −1 . Here, we designed and fabricated a novel nitrate sensor based on graphene field-effect transistors using triethylamine (TEA) as the probe molecule. The sensor uses graphene grown by chemical vapor deposition as the channel material. Triethylamine is modified on the graphene surface to detect nitrate anions. The sensitivity of the proposed TEA/graphene sensor reaches 1.3 nM (0.111 μg L −1 ), which is higher than that of mainstream sensors. This easy-to-fabricate and low-cost sensor also shows high specificity for other anions, such as Cl − , CO 3 2– , and SO 4 2− . Our study provides an excellent technical means for the rapid, accurate, and real-time monitoring of water pollution caused by nitrate anions.
研究领域:
环境科学
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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
Journal of Physical Chemistry C
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2023
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IF 3.7
Mingyang Chen,Renata Solarska,Ming Li
Despite considerable progress, the issues for precise evaluation of the surface-enhanced Raman scattering (SERS) substrate enhancement factor (EF) have not yet been completely solved until now. Herein, we verify that key aspects of probe molecules including initial concentration, footprint, and diffusion kinetics need to be taken into account for the experimental SERS EF measurement. The three factors collectively affect the surface coverage and thereby the determination of the number of probe molecules on the SERS substrate. We recommend that the measurement of the SERS EFs should be performed with complete surface coverage of probe molecules at steady-state equilibrium using relatively high initial concentrations. It has been demonstrated for the first time that the SERS EFs are independent of the initial concentration of probe molecules when exceeding the threshold initial concentration for complete surface coverage. This study highlights the importance of probe molecules in terms of diffusion kinetics and surface coverage for the accurate determination of the SERS EFs, which has yet to be addressed in the literature.
研究领域:
分析化学
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材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-9
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IF 17.694
Yin Jinglin,Kang Zhengzhong,Fu Yao,Cao Weicheng,Wang Yiran,Guan Hanxi,Yin Yu,Chen Binbin,Yi Xianfeng,Chen Wei,Shao Wei,Zhu Yihan,Zheng Anmin,Wang Qi,Kong Xueqian
The defects in metal-organic frameworks (MOFs) can dramatically alter their pore structure and chemical properties. However, it has been a great challenge to characterize the molecular structure of defects, especially when the defects are distributed irregularly in the lattice. In this work, we applied a characterization strategy based on solid-state nuclear magnetic resonance (NMR) to assess the chemistry of defects. This strategy takes advantage of the coordination-sensitive phosphorus probe molecules, e.g., trimethylphosphine (TMP) and trimethylphosphine oxide (TMPO), that can distinguish the subtle differences in the acidity of defects. A variety of local chemical environments have been identified in defective and ideal MOF lattices. The geometric dimension of defects can also be evaluated by using the homologs of probe molecules with different sizes. In addition, our method provides a reliable way to quantify the density of defect sites, which comes together with the molecular details of local pore environments. The comprehensive solid-state NMR strategy can be of great value for a better understanding of MOF structures and for guiding the design of MOFs with desired catalytic or adsorption properties.
研究领域:
材料科学
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化学
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固体核磁共振光谱
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催化
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吸附
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Nano
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2022
·Vol. 9
·期 8
·3004-3013
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IF 9.473
Qing Yang,Shaoying Zhang,Shouqing Ni,Yongchao Lai,Jinhua Zhan
The wide application of consumer goods containing silver nanoparticles (AgNPs) inevitably increases the accumulation of AgNPs in the environment and human exposure risk, which leads to an urgent need for accurate and efficient analytical methods to detect AgNPs. Herein, we proposed a filtration-based SERS method for sensitive and selective analysis of AgNPs. By adding Raman probe molecules (4-amino thiophenol) that can bind the surface of AgNPs, AgNPs can be identified by the characteristic signal of the probe and AgNP complexes. To improve the detection ability, an iodide-modified silver nanowire (AgNWs) membrane was chosen as a filter to separate and enrich AgNPs. Meanwhile, the signal intensity can be amplified due to the electromagnetic field interaction between AgNPs and AgNWs. Different types of AgNPs (coated with citrate, hydroxylamine hydrochloride and polyvinylpyrrolidone) can be detected and identified from other Ag species by the proposed method. Raman mapping was also performed on the membrane to obtain the distribution information of citrate-AgNPs with concentrations from 10−1 to 10−6 mg mL−1. A linear relationship (R2 = 0.998) between signal intensity and citrate-AgNP concentration indicates the possibility of quantification. Furthermore, AgNPs in antibacterial products without purification were successfully and efficiently detected by the proposed method. This work demonstrated the ability of the filtration-based SERS platform for analysing trace AgNPs in consumer goods.
研究领域:
分析化学
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环境科学
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材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
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