Multiwalled carbon nanotubes have unique properties allowing their use in a wide range of applications—from microelectronics to biomedical and polymer fields. Nevertheless, a crucial aspect for their use resides in the ease of handling them during the process. Here, we report a facile route to prepare multiwalled carbon nanotubes@octavinyl polyhedral oligomeric silsesquioxanes (MWCNT@POSS) nanocomposite. The method involves the formation of a covalent bond between carboxylated MWCNTs and OV-POSS using acid-catalyzed electrophilic addition reaction. The resulting nanocomposite have been characterized by Fourier transform infrared spectroscopy (FTIR), powder X-Ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The results confirmed that the formation of MWCNT@POSS nanocomposite did not deteriorate MWCNT structure or morphology. Here, we used a 1:1 ratio of carboxylated MWCNTs and OV-POSS and the POSS content in the nanocomposite was 39.5 wt%. 相似文献
Microchimica Acta - The authors describe an impedimetric nanosensor for aptamer-mediated detection of ATP. A triangular junction of polysilicon substrate is used as a transducer. The aptamer was... 相似文献
beta-O-N-Acetyl-d-glucosamine (O-GlcNAc) is a dynamic carbohydrate modification that is involved in cell signaling and has been implicated in a variety of disease states, including Alzheimer's and type-II diabetes. Despite the importance of this modification, little is known about the spatial and temporal localization of O-GlcNAc during signaling. This is due to the lack of methods for the study of O-GlcNAc in living cell systems. Herein we report the first genetically encoded FRET-based sensor for the detection of O-GlcNAc dynamics in live mammalian cells. 相似文献
This article describes a sensitive impedimetric method for the determination of human blood coagulation factor IX protein (FIX) which is present in extremely low concentration in serum. An interdigitated electrode (IDE) whose surface was layered with zinc oxide was modified with two kinds of probes. One is an antibody, the other an aptamer against FIX. A comparative study between anti-FIX aptamer and anti-FIX antibody showed the aptamer to possess higher affinity for FIX. A sandwich aptamer assay was worked out by using the FIX-binding aptamer on the surface of the IDE. It has a detection limit as low as 10 pM which makes it 4 to 30-fold more sensitive than any other method reported for FIX. Moreover, to practice detection in clinical samples, FIX was detected from the human blood serum by spiking. In our perception, the sensitivity of the ZnO-modified IDE presented here makes it a promising tool for sensing clinically relevant analytes that are present in very low (sub-pM) concentrations.
The authors describe an electrochemical method for the determination of the blood clotting factor IX (FIX). A nanogapped dielectrode (with a < 100 nm junction) was modified with antibody against FIX, and the resulting system was characterized by both impedance spectroscopy and voltammetry. In order to attain the improved sensitivity, gold nanoparticles were electrostatically attached to FIX. The current to voltage (I-V) measurement was carried out from 1 V to 5 V, where the entire calibration plot with 5 V was taken. This results in a limit of detection as low of 1 pM, which is much lower compared to the real concentration of FIX (87 nM) in human blood serum. The analytical range extends from 1 pM to 0.1 μM. The electrode is highly specific over other serum proteins.
Graphical abstract A nanogapped dielectrode with a <100 nm junction was modified with antibody against blood clotting factor IX and characterized by voltammetry. Gold nanoparticles were electrostatically attached to the analyte (blood clotting factor IX), and current/voltage (I-V) measurements were performed. Factor IX can be quantified with a limit of detection as low as 10 pM.
2′-Amino-1,1′-binaphthalen-2-ol (NOBIN) serves as a versatile chiral solvating agent (CSA) in the presence of trifluoromethanesulfonic acid (TFMS). The formation of a ternary complex has been established by NMR, UV–Vis, fluorescence and IR studies. The mechanism of interactions among the three components in the ternary complex has been proposed and the ternary complex structures of different diastereomers have been established by DFT based theoretical calculations. The present protocol has its ubiquity not only in the analysis of the enantiomeric composition of molecules possessing diverse functionalities, but also in determining the stereospecific assignment of hydroxy acids. 相似文献
The 16 kDa heat shock protein (16 kDa HSP) against Mycobacterium tuberculosis (MT), expressed during the growth phase of MT, is a potential target in diagnostic tests for tuberculosis (TB). We describe here a method for impedimetric determination of the antigen by using a nanogapped dielectric surface consisting of a silver support coated with a thin finger-shaped coating made from zinc oxide and gold and patterned through a lift-off process. The electrode was characterized by scanning electron microscopy, field emission scanning electron microscopy, atomic force microscopy, and energy-dispersive X-ray spectroscopy. Surface chemical functionalization and immobilization of antibody against the 16 kDa HSP was evidenced by FTIR. In order to improve the detection limit, the antigen was conjugated to 10 nm gold nanoparticles. The resulting biosensor is capable of detecting the 16 kDa HSP in concentrations as low as 100 fM. The method covers a wide analytical range that extends from 100 fM to 1 nM.
