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111.
In this paper, a label-free fluorescent method for glutathione (GSH) detection based on a thioflavin T/G-quadruplex conformational switch is developed. The sensing assay is fabricated depending on the virtue of mercury ions to form a thymine–thymine mismatch, which collapses the distance between two ssDNA and directs the guanine-rich part to form an intra-strand asymmetric split G-quadruplex. The newly formed G-quadruplex efficiently reacts with thioflavin T and enhances the fluorescent intensity. In the presence of GSH, Hg2+ is absorbed, destroying the G-quadruplex formation with a significant decrease in fluorescence emission. The proposed fluorescent assay exhibits a linear range between 0.03–5 μM of GSH with a detection limit of 9.8 nM. Furthermore, the efficacy of this method is examined using human serum samples to detect GSH. Besides GSH, other amino acids are also investigated in standard samples, which display satisfactory sensitivity and selectivity. Above all, we develop a method with features including potentiality, facility, sensitivity, and selectivity for analyzing GSH for clinical diagnostics.  相似文献   
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113.
Protein detection plays an important role in biological and biomedical sciences. The immunoassay based on fluorescence labeling has good specificity but a high labeling cost. Herein, on the basis of G-triplex molecular beacon (G3MB) and thioflavin T (ThT), we developed a simple and label-free biosensor for protein detection. The biotin and streptavidin were used as model enzymes. In the presence of target streptavidin (SA), the streptavidin hybridized with G3MB-b (biotin-linked-G-triplex molecular beacon) perfectly and formed larger steric hindrance, which hindered the hydrolysis of probes by exonuclease III (Exo III). In the absence of target streptavidin, the exonuclease III successively cleaved the stem of G3MB-b and released the G-rich sequences which self-assembled into a G-triplex and subsequently activated the fluorescence signal of thioflavin T. Compared with the traditional G-quadruplex molecular beacon (G4MB), the G3MB only needed a lower dosage of exonuclease III and a shorter reaction time to reach the optimal detection performance, because the concise sequence of G-triplex was good for the molecular beacon design. Moreover, fluorescence experiment results exhibited that the G3MB-b had good sensitivity and specificity for streptavidin detection. The developed label-free biosensor provides a valuable and general platform for protein detection.  相似文献   
114.
通过煅烧和静电自组装的方法制备了1T′ MoS2超薄纳米片和类石墨烯相氮化碳(g-C3N4)纳米片的复合材料. 该材料在光催化实验中展现出6.24 μmol?g?1?h?1的产氢速率, 优于贵金属铂修饰的g-C3N4纳米片的性能(4.64 μmol?g?1?h?1). 此外, 该复合材料在光催化降解有机染料甲基橙的实验中表现出0.19 min?1的催化速率, 而纯g-C3N4纳米片只有0.053 min?1的催化速率. 材料光催化性能的提升可归结于1T′MoS2 和g-C3N4之间的协同效应, 包括光吸收的增强以及因1T′MoS2优异电子导电性而得到的高效电荷分离.  相似文献   
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116.
We construct a map from the classifying space of a discrete Kac–Moody group over the algebraic closure of the field with p elements to the classifying space of a complex topological Kac–Moody group and prove that it is a homology equivalence at primes q different from p. This generalizes a classical result of Quillen, Friedlander and Mislin for Lie groups. As an application, we construct unstable Adams operations for general Kac–Moody groups compatible with the Frobenius homomorphism. Our results rely on new integral homology decompositions for certain infinite dimensional unipotent subgroups of discrete Kac–Moody groups.  相似文献   
117.
The excellent detection sensitivity in various matrices of T‐2 toxin (T‐2), which has cytotoxic and immunosuppressive effects in DNA and RNA synthesis, is a highly desirable characteristic. A sensitive molecularly imprinted electrochemical sensor was constructed for the selective detection of T‐2. In this study, iron ions (Fe3+) were introduced to increase the chelation of the metal ions and templates for preparing molecularly imprinted polymers (MIPs). With the increased chelation of the metal ions and templates, the selectivity and sensitivity of the MIPs were effectively improved. The imprinted sensor was successfully employed to detect T‐2 in cereals and human serum samples.  相似文献   
118.
To achieve specific cell targeting by various receptors for oligosaccharides or antibodies, a carrier must not be taken up by any of the very many different cells and needs functional groups prone to clean conjugation chemistry to derive well‐defined structures with a high biological specificity. A polymeric nanocarrier is presented that consists of a cylindrical brush polymer with poly‐2‐oxazoline side chains carrying an azide functional group on each of the many side chain ends. After click conjugation of dye and an anti‐DEC205 antibody to the periphery of the cylindrical brush polymer, antibody‐mediated specific binding and uptake into DEC205+‐positive mouse bone marrow‐derived dendritic cells (BMDC) was observed, whereas binding and uptake by DEC205? negative BMDC and non‐DC was essentially absent. Additional conjugation of an antigen peptide yielded a multifunctional polymer structure with a much stronger antigen‐specific T‐cell stimulatory capacity of pretreated BMDC than application of antigen or polymer–antigen conjugate.  相似文献   
119.
We report two anion-templated Ag40 clusters, [Ag40(E)4(SO4){S2P(OEt)2}24](PF6)6 (E = S, 1 ; Se, 2 ). The anionic templates were generated in situ from the decomposition of dithiophosphate (dtp) ligands. The extrusion of sulfur undergoes disproportionation reactions to generate sulfide and sulfate anions, which provide the source of templates in the subsequent cluster assembly reactions. Two Ag40 clusters display high similarity in their structures. The sulfide (selenide) anions and the central sulfate anion reveal a six-coordinate and a rare dodecametallic dodecaconnective pattern, respectively. Four near-equivalent [Ag10(E){S2P(OEt)2}6]2+ motifs were assembled via the connection of central sulfate anion to construct Ag40 clusters. The cluster cation, [Ag40(E)4(SO4){S2P(OEt)2}24]6+, displayed in T symmetry, is unprecedented in anion-templated silver clusters.  相似文献   
120.
Abstract

We have developed an economical and efficient method for the synthesis of medicinally and synthetically important indole-based triarylmethanes by using indoles and benzhydrols in the presence of propylphosphonic anhydride (T3P®). This methodology is an alternate approach for the C–C bond formation with good to excellent yields. In this T3P-mediated dehydration approach, the by-product is highly soluble in water, so that it can be done at larger scale also. In addition to that this efficient protocol has several advantages such as mild reaction conditions, short reaction time and operational simplicity. We have successfully synthesized pyrrole, imidazothiadiazole and imidazolo pyridine based triarylmethanes also.  相似文献   
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