查找使用阿拉丁产品的科研文献

Fluorescent MUA-stabilized Au nanoclusters for sensitive and selective detection of penicillamine

Yu Huan,Chen Xinfeng,Yu Long,Sun Mingtai,Alamry Khalid A.,Asiri Abdullah M.,Zhang Kui,Zapien Juan Antonio,Wang Suhua

In this study, we have developed a facile method for preparation of highly fluorescent Au nanoclusters (AuNCs) using 11-mercaptoundecanoic acid (MUA) as both the reducing and stabilizing agent. The as-prepared MUA functionalized AuNCs (MUA-AuNCs) have good water solubility, excellent photostability, and strong fluorescence emission at 610 nm with a quantum yield of 7.28% in water. The fluorescence of MUA-AuNCs was first quenched by copper ions through electron transfer, subsequently caused obvious restoration by competitive effect after adding penicillamine, making it a potential fluorescent sensor for penicillamine with a detection limit of 0.08 μM. Furthermore, the newly designed fluorescence “on-off-on” assay was explored for the measurement of penicillamine in complex real water and urine samples with satisfactory results.

MUA/NPAM/ZnO-coated Fiber-Optic surface plasmon resonance sensor for trace Chromium-Ion detection

Yuanli Xu,Wenlin Feng

A transmission fiber-optic surface plasmon resonance (SPR) sensor based on three-core optical fiber (TCF) coated with mercaptoundecanoic acid (MUA)/ nonionic polyacrylamide (NPAM)/zinc oxide (ZnO) composite film for the detection of chromium ions (Cr 3+ ) in water was proposed and fabricated. Multi-mode fiber (MMF) was spliced with both ends of TCF to form the MMF1-TCF-MMF2 sensing structure. The silver (Ag) film was deposited on the surface of TCF cladding, and then a uniform MUA/NPAM/ZnO composite film was coated on the outer surface of the Ag film to adsorb Cr 3+ , resulting in the wavelength shift of the SPR resonance peak. After adsorption of Cr 3+ , the refractive index of the sensing film changed and the resonance wavelength shifted about 62 nm. The detection limit of the sensor is about 0.029 μΜ (1.5 ppb), and the minimum detection concentration of Cr 3+ is about 0.2 µM (10 ppb), which is far lower than that of the World Health Organization standard (50 ppb). The sensor shows excellent selectivity, high sensitivity and good stability for the trace Cr 3+ , and has potential application for monitoring Cr 3+ in water.

MUA-modified Au nanocluster-driven fluorescence sensor for chromatographic test strips-based visual detection of patulin

Hongcheng Gao,Zhenzhen Xie,Shihao Xu,Changlong Jiang

The relationship between human health and patulin (PAT) in the diet is a complex and intertwined one. The development of a sensing approach for the field detection of patulin is crucial, as the current approach lacks real-time detection capabilities and is costly in terms of material and technology. This paper presents a portable ratiometric fluorescence sensor that can be used to rapidly, accurately, and efficiently detect patulin in food items at the point of origin. The sensor employs a combination of sulfhydryl functionalized gold nanoclusters (MUA-AuNCs) and blue emission carbon dots (B-CDs), which have been engineered to serve as highly effective “on-off” nanoprobes. The modified sulfhydryl ( SH) groups present on the gold clusters serve as specific recognition sites for patulin binding. The probes exhibit a discernible shift in hue, from orange-red to blue. The sensitivity detection limit (LOD) for patulin was found to be 0.019 μM, with a substantial linear correlation observed in the range of 0–2.2 μM. The objective of the combined chromatographic test strip and color recognition platform was to facilitate the sensitive, accurate, and real-time detection of patulin in foodstuffs, which is of paramount importance for the prevention of early disease. To facilitate rapid and straightforward preliminary testing of food security, it is anticipated that the integrated chromatographic strip ratiometric fluorescence sensing platform will be developed into portable home detection equipment.

11-MUA/Ag Modified Large-Core Fiber-Optic SPR Sensing Probe and Its Highly Sensitive Detection for Rabies Virus

Juan He,Qian Liao,Wenlin Feng

Mechanistic insights into transposon cleavage and integration by TnsB of ShCAST system

Ting Zeng,Jie Yin,Ziwen Liu,Zhaoxing Li,Yu Zhang,Yang Lv,Mei-Ling Lu,Min Luo,Meirong Chen,Yibei Xiao

Summary The type V-K CRISPR-associated transposons (CASTs) allow RNA-guided DNA integration and have great potential as a programmable site-specific gene insertion tool. Although all core components have been independently characterized structurally, the mechanism of how the transposase TnsB associates with AAA+ ATPase TnsC and catalyzes donor DNA cleavage and integration remains ambiguous. In this study, we demonstrate that TniQ-dCas9 fusion can direct site-specific transposition by TnsB/TnsC in ShCAST. TnsB is a 3′-5′ exonuclease that specifically cleaves donor DNA at the end of the terminal repeats and integrates the left end prior to the right end. The nucleotide preference and the cleavage site of TnsB are markedly different from those of the well-documented MuA. We also find that TnsB/TnsC association is enhanced in a half-integration state. Overall, our results provide valuable insights into the mechanism and application expansion of CRISPR-mediated site-specific transposition by TnsB/TnsC.