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991.
In this contribution, surface-enhanced Raman spectroscopy (SERS) based on conical holed glass substrates deposited with silver colloids was reported for the first time. It combines the advantages of both dry SERS assays based on plane films deposited with silver colloids and wet SERS assays utilizing cuvettes or capillary tubes. Compared with plane glass substrates deposited with silver colloids, the conical holed glass substrates deposited with silver colloids exhibited five-to ten-folds of increase in the rate of signal enhancement, due to the internal multiple reflections of both the excitation laser beam and the Raman scattering photons within conical holes. The application of conical holed glass substrates could also yield significantly stronger and more reproducible SERS signals than SERS assays utilizing capillary tubes to sample the mixture of silver colloids and the solution of the analyte of interest. The conical holed glass substrates in combination with the multiplicative effects model for surface-enhanced Raman spectroscopy (MEMSERS) achieved quite sensitive and precise quantification of 6-mercaptopurine in complex plasma samples with an average relative prediction error of about 4% and a limit of detection of about 0.02 μM using a portable i-Raman 785H spectrometer. It is reasonable to expect that SERS technique based on conical holed enhancing substrates in combination with MEMSERS model can be developed and extended to other application areas such as drug detection, environmental monitoring, and clinic analysis, etc. 相似文献
992.
Xi Dai Tao Zhang Zhi-Fang Du Xiang-Jian Cao Ming-Yu Chen Sheng-Wen Hu Jun-Ying Miao Bao-Xiang Zhao 《Analytica chimica acta》2015
We have developed the first two-photon colorimetric and ratiometric fluorescent probe, BICO, for the detection of bisulfite (HSO3−) in aqueous solution. The probe contains coumarin and benzimidazole moieties and can detect HSO3− based on the Michael addition reaction with a limit of detection 5.3 × 10−8 M in phosphate-buffered saline solution. The probe was used to detect bisulfite in tap water, sugar and dry white wine. Moreover, test strips were made and used easily. We successfully applied the probe to image living cells, using one-photon fluorescence imaging. BICO overcomes the limitations in sensitivity of previously reported probes and the solvation effect of bisulfite, which demonstrates its excellent value in practical application. 相似文献
993.
The Aerobic Oxidation and C=C Bond Cleavage of Styrenes Catalyzed by Cerium(IV) Ammonium Nitrate (CAN) 下载免费PDF全文
Lei Yu Yaping Huang Zengbing Bai Bingchun Zhu Kehong Ding Tian Chen Yuanhua Ding Yuguang Wang 《中国化学会会志》2015,62(6):479-482
The CAN‐catalyzed aerobic oxidation severed the C=C bond selectively through the single electron transfer mechanism, giving a green method to decompose olefins. Compared with the literature reported examples, this method required simple catalyst, cheap, abundant and clean oxidant and was very safe to operate due to the mild conditions. 相似文献
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Fabrication of the Monolithic Fiber for the Solid Phase Micro‐extraction of Malachite Green 下载免费PDF全文
A monolithic fiber of molecularly imprinted polymer (MIP) was prepared by in situ polymerization within the capillary with an inner diameter of 530 µm. It was carried out in 8 min by microwave irradiation using malachite green (MG) as a template molecule, α‐methacrylic acid (MAA) as a functional monomer, acetonitrile (ACN) as a porogenic solvent, ethylene dimethacrylate (EDMA) as a crosslinker, azodiiso‐butyronitrile (AIBN) as a thermal initiator. The resulted MIP fibers were pushed out from the capillary, eluted and inserted in the capillary again, which successfully used for the solid phase microextraction (SPME) procedure. The factors affecting the extraction of MG, such as the molar ratio of template/monomer (MG/MAA), concentration of NaCl, extraction and desorption time, and extraction and desorption solvents were investigated in detail. The selectivity of the MIP fibers was compared using MG analogues crystal violet (CV) and non‐analogue Sudan II. It was also employed for the pretreatment of trace MG in the fish feed followed by high‐performance liquid chromatography (HPLC) detection. Under the optimal conditions, the linear range of MG was 10‐600 μg/L, the detection limit (LOD) was 1.23 μg/L and the recovery of spiked fish feed sample was 88.7~113.9%. 相似文献
996.
Experimental Investigation on Binary Phase Diagram of the Thermotropic Phase Transitions Compounds (n‐CnH2n+1R3)2ZnCl4 下载免费PDF全文
The thermotropic phase transitions compounds (n‐CnH2n+1R3)2ZnCl4 as well as a series of their binary mixtures were prepared by a solution reflux method from their ethanol solutions. The experimental subsolidus binary phase diagram of [n‐C18H37N(CH3)3]2ZnCl4‐[n‐(C18H37)2N(CH3)2]2ZnCl4 is constructed over the entire composition range by differential scanning calorimetry(DSC) and X‐ray. Experi‐ mental results indicate one stable intermediate phase [n‐C18H37N(CH3)3] [n‐(C18H37)2N(CH3)2]ZnCl4 at WC18C3Zn %=59.75 %, and two invariant three phase equilibria, which shows two eutectoid temperatures: Te1 at 310±1 K for eutectoid point WC18C3Zn %=36.24 %, Te2 at 313±1 K for eutectoid point WC18C3Zn %=80.17 %. These three noticeable solid‐solution ranges are α‐phase at the left, ?‐phase at the right, and ψ‐phase in the middle of the phase diagram. It is (n‐CnH2n+1R3)2ZnCl4 systems as phase change materials that are characterized the phase transition temperatures T in the range of 310 to 340 K, the transition enthalpies ΔH in the range of 38.40 and 168.72 J/g between two polymorphic forms. 相似文献
997.
Reactions of a,ß‐unsaturated N‐benzenesulfonyl Imine – N‐[(2E)‐3‐phenyl‐2‐propen‐1‐ylidene]benzenesulfonamide with Methyllithium 下载免费PDF全文
α,β‐Unsaturated N‐benzenesulfonyl imine 1 was treated with 1.1 eq methyllithium to afford 1,2‐addition adduct as a sole product. However, when compound 1 was treated with 2 eq MeLi, 1,2‐addition product, benzenesulfonamide derivative 3 and 2H‐1,2‐benzothiazine 1,1‐dioxide derivatives 4 and 5 were isolated. 相似文献
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