Applied Sciences-Basel
·
2022
·Vol. 12
·期 21
·11202
·
IF 2.838
Jie Yang,Zhibo Zhou,Tianji Lu,Ling Shen
The present work reports the identification of inorganic and organic materials applied in gildings of Kizil Grottoes mural paintings, located in the western part of China. A total of 10 gold gilding samples were collected from caves dated in the fourth–seventh century AD. In this research, optical microscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), UV fluorescence microscopy, and pyrolysis gas chromatography–mass spectrometry (Py-GC/MS) analyses were carried out to clarify the mordant materials and the coating materials on the foils. This research reports some new finds of the gilding technique in Kizil grottoes, such as oil and lac resin being used as mordant to provide a binding medium for gold gilding, gold powder probably being used as pigment, and some organic dyes being well preserved under gold foil. These interesting findings not only provide scientific evidence for us to understand the materials and techniques of gold gildings on Kizil Grottoes murals, but also illustrate material trade and technique exchanges along the Silk Road in the past.Keywords:gilding;lac resin;organic materials;Kizil Grottoes
研究领域:
考古学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2020
·
IF 4.049
Hanzhi Zhang,Chunli Lou,Jing Li,Jingwu Kang
A method for the preparation of an on-column ESI emitter used as the sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry (MS) was developed. The emitter was directly fabricated at the outlet end of the separation capillary which was etched with HF solution to a symmetrical tip. The tip was covered with a small piece of gold foil which was fixed by epoxy resin glue for electrical contact. Such a prepared ESI emitter can produce a stable ESI signal over the wide range of flow rate from 50 nL/min to 800 nL/min. The performance of the CE-MS with the sheathless interface was evaluated by using the separation of four alkaloids. It was found that the strong electroosmotic flow produced by the multiple polyelectrolyte coating on the capillary is necessary for maintaining a stable MS signal. Effect of the running buffer composition, concentration and the CE separation voltages on the ESI signal strength were investigated. The absolute detection limits for the alkaloids was determined as fmol level. Moreover, the CE-MS was applied for the analyses of trypsin digestion of cytochrome C and small molecular organic anions. The emitter performed very stable with a lifetime of at least 180 h.
研究领域:
分析化学
·
生物分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2025
·
IF 6.3
Junyu Yuan,Shengwei Tang,Junlong Niu,Yulin Liu,Chunyang Jia
The conductive layer of the conductive gold electrode, firmly combined with the flexible substrate and possessing high reflectance, is key factor in achieving wide-band regulation of electrochromic devices. However, existing preparation methods such as physical vapor deposition and chemical gold plating are costly and complex. In response to the wide-band regulation requirements of electrochromic devices, a flexible conductive gold electrode with high reflectance was prepared using gold foil as the conductive material. This process is simple and incurs no processing loss. A polyaniline (PANI) film was deposited on the surface of the flexible conductive gold electrode through cyclic voltammetry, and a PANI-based electrochromic device was subsequently prepared. The electrochromic device exhibits striking color changes in visible light, including bright yellow, green, and dark green. Moreover, it demonstrates excellent regulation performance in the near-infrared band, with a reflectance change of up to 72.5 %. In the mid-infrared range, it shows good emissivity regulation performance, with an emissivity change reaching 0.45. This device has promising application prospects in solar radiation regulation. Demonstration experiments verified that in the solar radiation band, it has a solar absorption rate change range of 0.34–0.90. Under standard sunlight irradiation, the device achieves a temperature regulation of 9.2 °C.
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
RSC Advances
·
2016
·Vol. 6
·期 49
·43724-43731
·
IF 3.289
Yingchun Li,Lu Zhang,Jiang Liu,Shu-Feng Zhou,Khalid Abdullah Al-Ghanim,Shahid Mahboob,Bang-Ce Ye,Xueji Zhang
Warfarin sodium (WFS) is a widely used oral anticoagulant drug but has a narrow therapeutic window. Since traditional detection methods applied for therapeutic drug monitoring suffer some shortcomings, including difficulty in obtaining timely reports, high costs and tedious operation, it is necessary to develop a detection system for the rapid monitoring of WFS in biological samples. Here we report a novel electrochemical sensor, which was facilely fabricated by coupling nanoporous gold leaf (NPGL) with molecularly imprinted polymer (MIP) to afford ultrasensitive and selective determination of WFS. The morphological characterization via scanning electron microscopy proved the successful modification of the sensor by NPGL followed with MIP layer modification. The influencing parameters including the type of monomer, pH and molar ratio of template to monomer were optimized during electro-polymerization. Using Fe(CN)63−/4− as a probe acting as an electrical indicator, a linear relationship of the current response versus the concentration of WFS was obtained in the range from 1.0 × 10−10 to 8.0 × 10−8 M under the optimal experimental conditions, with a detection limit of 4.1 × 10−11 M (S/N = 3). In addition, the as-prepared sensor exhibited specific detection of WFS over its structural analogues and interferents, and the established electrochemical approach was validated using the standard method – high performance liquid chromatography. Eventually, rapid and accurate determination of WFS in human blood was carried out after easy sample pretreatment.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-8
·
IF 5.578
Li Yingchun,Liu Yuan,Liu Jie,Liu Jiang,Tang Hui,Cao Cong,Zhao Dongsheng,Ding Yi
Electrochemical nanosensors based on nanoporous gold leaf (NPGL) and molecularly imprinted polymer (MIP) are developed for pharmaceutical analysis by using metronidazole (MNZ) as a model analyte. NPGL, serving as the loading platform for MIP immobilization, possesses large accessible surface area with superb electric conductivity, while electrochemically synthesized MIP thin layer affords selectivity for specific recognition of MNZ molecules. For MNZ determination, the hybrid electrode shows two dynamic linear range of 5 × 10 −11 to 1 × 10 −9 mol L −1 and 1 × 10 −9 to 1.4 × 10 −6 mol L −1 with a remarkably low detection limit of 1.8 × 10 −11 mol L −1 (S/N = 3). In addition, the sensor exhibits high binding affinity and selectivity towards MNZ with excellent reproducibility and stability. Finally, the reliability of MIP-NPGL for MNZ detection is proved in real fish tissue samples, demonstrating the potential for the proposed electrochemical sensors in monitoring drug and biological samples.
研究领域:
分析化学
·
材料科学
·
电化学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2021
·
IF 6.057
Min-Xi Li,Yao Chen,Zeng-Ping Chen,Ru-Qin Yu
Herein, a label free and sensitive miRNA detection method with enhanced practical applicability was developed based on the locked nucleic acid (LNA) assisted repeated fishing amplification strategy. The working mechanism of the proposed method is as follows: 1) a DNA probe (i.e, L-DNA) with LNA bases is immobilized onto the surface of a gold foil. The L-DNA hybridizes with the 3′ terminus of the first strands of complementary deoxyribonucleic acid (cDNA) of the target miRNA in the test samples; 2) The protruding 5′ terminus of the cDNA serves as a ‘fishhook’ to repeatedly fish the products of a hybridization chain reaction (HCR) out from a ‘reaction tube’; 3) The HCR products can be unloaded from the gold foil into a ‘product tube’ through temperature-controlled dehybridization; 4) The concentration of the target miRNA is determined based on the fluorescence intensity generated by the addition of SYBR-Green I (SG) into the ‘product tube’. The proposed platform was applied to the detection of miRNA-122 in cell lysate samples and obtained quantitative results with accuracy comparable to the quantitative reverse transcription PCR method (qRT-PCR). It is worth pointing out that the proposed platform achieved a limit of detection value of 2.9 fM for miRNA-122 by a simple but effective LNA-assisted repeated fishing amplification strategy instead of complicated enzyme-based amplification techniques. It is reasonable to expect that the proposed method provides a competitive alternative for designing practically applicable, cost-effective and label-free miRNA detection methods.
研究领域:
生物化学
·
分子生物学
·
纳米技术
·
分析化学
✓ 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）