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861.
A sensing approach is applied to encode quantitative enzymatic activity information into DNA sequence populations. The method utilizes DNA‐linked peptide substrates as activity probes. Signal detection involves chemical manipulation of a probe population downstream of sample exposure and application of purifying, selective pressure for enzyme products. Selection‐induced changes in DNA abundance indicate sample activity. The detection of protein kinase, protease, and farnesyltransferase activities is demonstrated. The assays were employed to measure enzyme inhibition by small molecules and activity in cell lysates using parallel DNA sequencing or quantitative PCR. This strategy will allow the extensive infrastructure for genetic analysis to be applied to proteomic assays, which has a number of advantages in throughput, sensitivity, and sample multiplexing.  相似文献   
862.
Nucleic acid aptamers are short synthetic DNA or RNA sequences that can bind to a wide range of targets with high affinity and specificity. In recent years, aptamers have attracted increasing research interest due to their unique features of high binding affinity and specificity, small size, excellent chemical stability, easy chemical synthesis, facile modification, and minimal immunogenicity. These properties make aptamers ideal recognition ligands for bioanalysis, disease diagnosis, and cancer therapy. This review highlights the recent progress in aptamer selection and the latest applications of aptamer‐based functional probes in the fields of bioanalysis and biomedicine.  相似文献   
863.
SnFe2O4 nanocrystals (NC), prepared with a simple one‐step carrier‐solvent‐assisted interfacial reaction process, were developed as highly efficient catalysts for hydrogen peroxide sensing. These NCs, with a size of around 7 nm, served as the sensing catalyst and were decorated onto the pore surfaces of a porous fluorine‐doped tin oxide (PFTO) host electrode, prepared from commercial FTO glass with a simple anodic treatment, to form the sensing electrode for hydrogen peroxide. The SnFe2O4 NCs‐loaded PFTO electrode exhibited an ultra‐high sensitivity of 1027 mA m ?1 cm?2 toward hydrogen peroxide, outperforming Pt NCs‐loaded PFTO electrodes. The SnFe2O4 NCs‐loaded PFTO electrode proved a promising relatively low cost, high performance sensing electrode for hydrogen peroxide.  相似文献   
864.
865.
We have introduced a new ABA‐type amphiphilic block copolymer consisting of functional oligourethane hydrophobic blocks and two polyethylene glycol (PEG) hydrophilic blocks. The polymer was synthesized in a single step by step‐growth polymerization between two monomers, namely tetraphenylethylene (TPE)‐diol and hexamehylene di‐isocyanate in the presence of a monofunctional impurity PEG‐2000. The polymer exhibits facile self‐assembly in water by synergistic effects of H‐bonding and π–π interaction among the oligourethane core, leading to the formation of robust nanoparticles with remarkable aggregation‐induced emission (AIE). These nanoparticles show very low critical aggregation concentration, stability over a large pH window, and excellent biocompatibility as revealed by an MTT assay. Cellular imaging with cancer cells showed facile cellular uptake and, more importantly, retention of AIE in cellular milieu for long times, which was successfully utilized for long‐term cancer cell tracking.  相似文献   
866.
Early detection of amyloid fibrils is very important for the timely diagnosis of several neurological diseases. Thioflavin‐T (ThT) is a gold standard fluorescent probe for amyloid fibrils and has been used for the last few decades. However, due to its positive charge, ThT is incapable of crossing the blood–brain barrier and cannot be used for in vivo imaging of fibrils. In the present work, we synthesized a neutral ThT derivative, 2‐[2’‐Me,4’‐(dimethylamino)phenyl]benzothiazole (2Me‐DABT), which showed a strong affinity towards the amyloid fibrils. On association with the amyloid fibrils, 2Me‐DABT not only showed a large increase in its emission intensity, but also, unlike ThT, a large blueshift in its emission spectrum was observed. Thus, unlike ThT, 2Me‐DABT is a potential candidate for the ratiometric sensor of the amyloid fibrils. Detailed photophysical properties of 2Me‐DABT in amyloid fibrils and different solvent media were studied to understand its sensory activity. Fluorescence resonance energy transfer (FRET) studies suggested that the sites of localization for ThT and 2Me‐DABT in amyloid fibrils are not same and their average distance of separation in amyloid fibrils was determined. The experimental data was nicely supported by molecular docking studies, which confirmed the binding of 2Me‐DABT in the inner core of the amyloid fibrils.  相似文献   
867.
即时检测(POCT)是在病人旁边或现场进行的检测,因其简单、快速、便携且不受场所限制已成为目前体外分子诊断技术发展的一支风向标。而生物传感器以其快速、灵敏、高效、便携及易于自动化、微型化等优点在发展现场即时检测技术中具有非常大的潜力。近年来,随着生物传感技术、互联网技术的发展及各种新技术、新方法的兴起和融合,POCT技术和方法得到了实质性发展。本文简要介绍了生物传感器的分类和生物传感器在POCT中的应用现状,综述了近年来各类生物传感器在面向POCT检测应用的研究进展。生物传感器根据类型主要分为基于微流控芯片的生物传感器、基于纸的生物传感器、基于纳米材料的生物传感器、基于手机检测平台的生物传感器及集成的生物传感器等,并对这些传感器平台在POCT检测方面的应用做了阐述,最后对生物传感器在POCT应用中存在的问题进行了讨论,并对其发展趋势及前景做了展望。  相似文献   
868.
Nicola M. Howarth 《Tetrahedron》2005,61(37):8875-8887
Adenine-, cytosine- and thymine-containing peptide nucleic acid (PNA) monomers have been synthesized in which either diacetylenic or stearoyl moieties are attached to the N-or C-terminus; the diacetylenic group is embedded within a long hydrocarbon chain. A range of analogous lipophilic functionalized PNA oligomers have been prepared using either solid phase synthesis or a post-synthetic solution phase procedure following cleavage of the PNA oligomer from the solid support. Selected functionalized PNA monomers and oligomers have been incorporated into liposomal polydiacetylenes and characterized by UV-vis absorption spectroscopy. Preliminary investigations show that blue PDA-liposomes containing thymine-based PNAs can be formed and that production of liposomes with other PNA systems are viable.  相似文献   
869.
Protein micro-/nanoarrays are becoming increasingly important in systematic approaches for the exploration of protein-protein interactions and dynamic protein networks, so there is a high demand for specific, generic, stable, uniform, and locally addressable protein immobilization on solid supports. Here we present multivalent metal-chelating thiols that are suitable for stable binding of histidine-tagged proteins on biocompatible self-assembled monolayers (SAMs). The architectures and physicochemical properties of these SAMs have been probed by various surface-sensitive techniques such as contact angle goniometry, ellipsometry, and infrared reflection-absorption spectroscopy. The specific molecular organization of proteins and protein complexes was demonstrated by surface plasmon resonance, confocal laser scanning, and atomic force microscopy. In contrast to the mono-NTA/His6 tag interaction, which has major drawbacks because of its low affinity and fast dissociation, drastically improved stability of protein binding by these multivalent chelator surfaces was observed. The immobilized histidine-tagged proteins are uniformly oriented and retain their function. At the same time, proteins can be removed from the chip surface under mild conditions (switchability). This new platform for switchable and oriented immobilization should assist proteome-wide wide analyses of protein-protein interactions as well as structural and single-molecule studies.  相似文献   
870.
In the past decade, wearable biosensors have radically changed our outlook on contemporary medical healthcare monitoring systems. These smart, multiplexed devices allow us to quantify dynamic biological signals in real time through highly sensitive, miniaturized sensing platforms, thereby decentralizing the concept of regular clinical check-ups and diagnosis towards more versatile, remote, and personalized healthcare monitoring. This paradigm shift in healthcare delivery can be attributed to the development of nanomaterials and improvements made to non-invasive biosignal detection systems alongside integrated approaches for multifaceted data acquisition and interpretation. The discovery of new biomarkers and the use of bioaffinity recognition elements like aptamers and peptide arrays combined with the use of newly developed, flexible, and conductive materials that interact with skin surfaces has led to the widespread application of biosensors in the biomedical field. This review focuses on the recent advances made in wearable technology for remote healthcare monitoring. It classifies their development and application in terms of electrochemical, mechanical, and optical modes of transduction and type of material used and discusses the shortcomings accompanying their large-scale fabrication and commercialization. A brief note on the most widely used materials and their improvements in wearable sensor development is outlined along with instructions for the future of medical wearables.  相似文献   
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