共查询到20条相似文献,搜索用时 15 毫秒
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Ya Zhang Kailimai Su Yingshuang Ha Weifeng Chen Chenghua Sun 《Analytical letters》2019,52(12):1888-1899
Molecular imprinting and surface enhanced Raman scattering (SERS) were used to prepare a core-shell Ag@molecularly imprinting polymer (MIP) for the determination of p-nitroaniline. The obtained Ag@MIP exhibits a detection limit of 10?12 M, which demonstrates higher sensitivity toward p-nitroaniline than conventional approaches. In addition, the Ag@MIP shows good recyclability, and simultaneously offers better stability and high SERS activity for recognizing target molecules. To characterize the high SERS activity of the SERS-MIP hybrid material, a possible mechanism for the SERS substrate is proposed involving enhancement by the MIP. This study is expected to provide an alternative approach for the determination of p-nitroaniline in aqueous environments. 相似文献
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为实现鸭肉中环丙沙星(CIP)残留的快速检测,建立了一种鸭肉中CIP残留的表面增强拉曼光谱(SERS)快速检测方法。进行了增强基底的紫外-可见吸收光谱分析和鸭肉中CIP残留检测的SERS可行性分析。通过单因素实验,确定了金胶加入量、含CIP的鸭肉提取液加入量、氯化钠溶液加入量和吸附时间。在最佳实验条件下,建立了鸭肉中CIP残留的SERS检测的标准工作曲线,决定系数(R2)为0.987 9,预测样本中CIP的平均回收率为97.0%~111.7%。实验结果表明,鸭肉中CIP残留的SERS快速检测方法是可行的。 相似文献
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联合红外、拉曼光谱及其在金/银核-壳粒子上的表面增强拉曼散射(SERS)光谱表征了乐果和氧化乐果两种乐果类似物, 归属并分析了两乐果类似物中P=S与P=O的不同而引起的振动模式, 峰位变化及其酸碱影响. 振动光谱显示, ν(P=O), ν(P=S)分别在690, 650 cm-1附近, 两分子结构中对应的ν(NH), νs(CH2), ν(C-O), ν(O=C-N) II, ν(S-CH2)振动峰位中差异显著, 但νas(CH3), ν(P-O-C), ν(O=C-N) I, δ(CH3), ν(C-C), ν(C-C=O)则基本对应. 在金/银核-壳粒子基底上, 进一步探讨了两乐果类似物中各基团在不同浓度, pH值及酸、碱水解历程条件下的SERS变化规律, 并运用SERS机理并结合TEM初步阐述了两乐果类似物在金/银核-壳粒子表面的吸附状态. 相似文献
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顶空液相微萃取-气相色谱质谱法快速测定饮料中苯和甲苯 总被引:8,自引:0,他引:8
建立了顶空液相微萃取-气相色谱质谱法测定饮料中苯和甲苯的方法。在对顶空液相微萃取(head-space liquid-phase microextraction,HS-LPME)实验条件优化的基础上,确定了最佳实验条件:以1.6μL正辛醇作为有机萃取剂,在萃取温度为50℃、萃取时间为5min,搅拌速度为750r/min,液滴离萃取瓶瓶塞2.0cm的条件下,萃取4.00mLNaCl含量为4.00mol/L的样品水溶液,取0.4μL的有机萃取剂直接进样。实验结果表明,苯和甲苯的富集倍数分别为94和191,方法检出限分别为0.090μg/L和0.093μg/L,线性范围为0.5~60μg/L(r>0.999)。将该方法应用于饮料中苯和甲苯的测定,回收率为93.6%和98.0%,相对标准偏差(RSD)为3.94%和2.69%。方法简单、快速且成本低、可信度高,适用于饮料和水样中苯和甲苯的快速分析。 相似文献
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《Analytical letters》2012,45(8):1544-1557
Geosmin (GSM) and 2-methylisoborneol (MIB) were extracted from water samples, adsorbed in organic solvent microdrop by headspace liquid-phase microextraction (HS-LPME), and were analyzed by gas chromatography-mass spectrometry (GC-MS). Influence factors such as the extraction solvent types, headspace and microdrop volumes, stirring rate, equilibrium and extraction time, and ionic strength for HS-LPME efficiency were thoroughly evaluated. Under optimized extraction and detection conditions, the calibration curves of GSM and MIB were linear in the range of 5–1000 ng/L. The detection limits of GSM and MIB were 1.1 and 1.0 ng/L, respectively. Average recoveries of 95.45–113.7% (n = 5) were obtained and method precisions were also satisfactory. Trace levels of the off-flavor compounds at ng/L in tap water and raw water were successfully quantified. 相似文献
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该文开发了一种基于Au@Ag纳米颗粒(Au@AgNPs)快速检测法莫替丁(FMD)的表面增强拉曼光谱(SERS)方法。通过种子介导法合成了Au@AgNPs,再采用场电子发射显微镜(SEM)、透射电子显微镜(TEM)、紫外可见吸收光谱(UV-Vis)和X射线衍射仪(XRD)对Au@AgNPs进行表征,以罗丹明6(RG6)为分子探针对合成的Au@AgNPs的SERS性能进行了测试。结果显示,合成的Au@AgNPs形貌均匀,具有良好的增强效果,增强因子为6.66×105,将其用于法莫替丁标准溶液的SERS检测,在0.5~50μmol/L范围内法莫替丁浓度的对数和1 540 cm-1处峰强度的对数具有较好的线性关系,相关系数(r2)为0.978,检出限(LOD)为4.18×10-8 mol/L。在同样的条件下对稀释血浆中的法莫替丁进行了SERS检测,LOD为1.11×10-7 mol/L,加标回收率为91.6%~122%,相对标准偏差为6.6%~12%,表明该方法快速、灵敏,在生物样本... 相似文献
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G. Vourlias N. Pistofidis E. Pavlidou K. Chrissafis 《Journal of Thermal Analysis and Calorimetry》2009,95(1):63-68
In the present work the oxidation behavior of ageing treated steel was examined up to 1000°C in different environments (O2 and CO2) and with different heating rates. The examination was conducted by means of thermogravimetric analysis, scanning electron
microscopy and X-ray diffraction. In this study it was deduced that in the case of O2 an oxide scale is formed on top of the steel. The oxidation is uniform and the growth of the scale is more intent at low
heating rate. It consist of different Fe, Mn, Mo and Cr oxides which are adjusted in the form of layers. This phenomenon was
explained by the different diffusion coefficients of each metal in the already formed scale. Regarding the oxidation in CO2, the scale formation takes place at a lower temperature than in the case of O2. Hence the examined substrate is more vulnerable in CO2. 相似文献
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A graphene monolithic column was fabricated in a capillary using π-electron-rich poly(N-vinylcarbazole-divinylbenzene) as the supporter through in situ one-step polymerization for the enrichment of trace benzodiazepines in biological samples. This new three-dimensional monolith showed uniformity and a continuous column bed; more importantly, it retained the unique properties of graphene that are typically associated with individual graphene sheets. Based on the large delocalized π-electron system, graphene forms π–π stacking interactions with benzodiazepines and benzene rings of poly(N-vinylcarbazole-divinylbenzene), which not only enhance the extraction performance for benzodiazepines compared to the neat polymer but also provide chemical stability of the graphene monolith. Moreover, several factors likely to affect the extraction, including ionic strength, sample pH, sample volume, and eluant volume were studied in detail. The optimized method gave a linear range of 0.005–1?ng?mL?1, and detection limits of 1.12–2.35?ng?L?1. Finally, the graphene monolith was successfully applied to the separation and enrichment of benzodiazepines from urine and hair samples coupled with high-performance liquid chromatography–mass spectrometry. The recoveries were in the range of 78.6–85.6% for urine and 87.2–94.3% for hair with relative standard deviations of 3.4–6.9 and 2.9–8.3%, respectively. 相似文献
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该文建立了基于表面增强拉曼光谱(SERS)技术检测水和尿液中舒芬太尼的方法。首先制备了银溶胶SERS基底并进行表征。随后通过理论计算和实验对比,对舒芬太尼的拉曼特征峰进行了归属。通过探索最佳实验条件,确定了促凝剂及其浓度。对水和人工尿液中的舒芬太尼进行了SERS检测,检出限分别为0.09μg/mL和1.55μg/mL。水和尿液中舒芬太尼的特征峰(1 004 cm~(-1))强度与舒芬太尼质量浓度在一定范围内呈线性关系,相关系数(r~2)分别为0.979和0.968。水和尿液中舒芬太尼的回收率分别为96.3%~107%和95.8%~106%,相对标准偏差分别为4.2%~4.7%和3.3%~5.2%。该方法具有快速、准确、无损、操作简便等优点,为水和尿液中舒芬太尼的快速检测打下了良好的基础。 相似文献
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《Analytical letters》2012,45(12):1930-1940
A simple integrated agarose microchip-based substrate is reported for surface enhanced Raman spectroscopy. The substrate was evaluated for the determination of sodium thiocyanate in milk. The limit of detection was 5 × 10?7 grams per milliliter. The microarray design allowed the synchronous processing of many samples. The reported procedure is green and practical for on-site determination of sodium thiocyanate in milk with potential for additional applications. 相似文献
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表面增强拉曼光谱(SERS)的广泛应用源于优良的基底,目前主要局限在粗糙贵金属及胶体纳米颗粒材料.而半导体的光谱高稳定性和再现性,使其成为制备SERS基底的新型材料,但对于其SERS增强机理的研究仍存在极大挑战.本工作以典型的形貌新颖、尺寸均一的扫帚状n型纳米半导体ZnO为SERS基底材料,通过调节激发光的波长和选用具有不同对位取代基的对硝基苯硫酚(PNTP)、苯硫酚(TP)、对氨基苯硫酚(PATP)为探针分子,系统地研究了纳米ZnO的SERS增强行为,估算了其表面增强因子(EF),分离了化学增强作用中非共振增强效应和电荷转移效应对SERS的贡献.研究表明三种分子在不同激发光作用下的增强因子为10至35,其中PNTP分子约10倍的增强主要来自于因吸附而造成极化率变化的非共振增强效应,TP和PATP分子20~35倍的增强则是由非共振增强效应与光子驱动电荷转移效应共同作用所致,光子能量越高,SERS增强效应越强.且因分子与ZnO间电荷转移的速率较慢导致ZnO表面电荷转移增强效应较贵金属低1~2个数量级.本研究结果为新型半导体SERS基底的制备及调控提供了新思路. 相似文献
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Boron Nitride Nanosheets Improve Sensitivity and Reusability of Surface‐Enhanced Raman Spectroscopy 下载免费PDF全文
Qiran Cai Srikanth Mateti Prof. Wenrong Yang Dr. Rob Jones Dr. Kenji Watanabe Prof. Takashi Taniguchi Prof. Shaoming Huang Prof. Ying Chen Dr. Lu Hua Li 《Angewandte Chemie (International ed. in English)》2016,55(29):8405-8409
Surface enhanced Raman spectroscopy (SERS) is a useful multidisciplinary analytic technique. However, it is still a challenge to produce SERS substrates that are highly sensitive, reproducible, stable, reusable, and scalable. Herein, we demonstrate that atomically thin boron nitride (BN) nanosheets have many unique and desirable properties to help solve this challenge. The synergic effect of the atomic thickness, high flexibility, stronger surface adsorption capability, electrical insulation, impermeability, high thermal and chemical stability of BN nanosheets can increase the Raman sensitivity by up to two orders, and in the meantime attain long‐term stability and extraordinary reusability not achievable by other materials. These advances will greatly facilitate the wider use of SERS in many fields. 相似文献
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Ecaterina Matei Andra Predescu Andrei Berbecaru Claudia Tarcea Cristian Predescu 《Analytical letters》2019,52(14):2180-2187
Photocatalysis has become common and nanomaterials having photocatalytic functions have been widely characterized. At present, among the many candidates for photocatalysis, TiO2 is almost the only material suitable for industrial use. In this paper, we present a TiO2 synthesis starting from Ti sheets put in contact with a mixture of 0.1 N NaOH and acetone for 72?hours under ambient conditions. The obtained sheets were washed with distilled water and ethanol, and the surface was analyzed for its structural and morphological properties. Thus, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) investigations indicated the formation of TiO2 on the edges of nanometer circles on the surface of the Ti sheets. For characterizing the photocatalytic capacity for wastewater treatment, Ti sheets with TiO2 on the surface contacted with methylene blue solutions at room temperature under ultraviolet light. The degradation of the methylene blue concentration was measured by ultraviolet–visible spectroscopy, demonstrating 99.94% efficiency for wastewater treatment using the obtained material. 相似文献
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A novel method for the dynamic determination of cetirizine dihydrochloride in urine using surface enhanced Raman scattering (SERS) has been developed. Comparison of SERS activities between gold and silver colloid was made based on the analysis of the transmission electron micrographs and the SERS spectra, revealing that silver colloid is much more efficient on the signal enhancement performance. The primary sites of the adsorption on the nanoparticle surface were represented by the feature peaks of piperazine at ca. 1050?cm?1 and phenyl rings at ca. 1630?cm?1, respectively. The best signal response was extracted at pH 7 at the Cl?:Ag+ molar ratio of 2:1. The matrix effect was eliminated by subtracting the spectral contribution of the blank urine from the sample spectra. Sample preparation procedures were minimized. Quantification could be simply accomplished on the predicted versus actual concentration curve, within the Raman shift range from 500 to 2500?cm?1. Neither modeling nor complicate calculation was required. The method was shown to be specific and applicable for drug urine concentration monitoring in situ. 相似文献
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采用元素分析、扫描电镜和透射电镜等分析方法对渣油原料中的沥青质、加氢处理后的沥青质及添加高芳香性轻循环油(LCO)反应后的沥青质进行对比研究。结果发现,渣油加氢处理前后沥青质的表面呈现出光滑表面和多孔的球形颗粒表面两种完全不同的形貌。渣油加氢前后沥青质的芳核堆砌表现出明显的长程无序局部有序的特征;加氢处理后的沥青质芳核片层易于堆砌,出现了多层堆砌、长程有序的类石墨结构。渣油中高芳香性LCO的添加有利于促进沥青质的加氢反应、改善沥青质芳核系统在渣油加氢处理过程中的聚集行为。 相似文献