Escherichia coli O157: H7 (E. coli O157: H7) is a foodborne pathogenic bacterium which can cause fever, diarrhoea and vomiting in humans. Thus, a rapid, simple, and specific bioprobe for pathogen detection in contaminated foods has been attracted more and more attention. In this work, the strong fluorescent amino-functionalized graphene quantum dots (af-GQDs) were prepared by hydrothermal method. The microtopographic height, surface morphology and spectroscopic properties of af-GQDs are characterized by the high resolution transmission electron microscope (HRTEM), atomic force microscope (AFM), UV-vis, fluorescence, Raman spectroscopic techniques. All the results showed that the af-GQDs can be effectively applied in the preparation of biocompatible immunofluorescence probe and in the detection of E. coli O157: H7. The minimum detection limit is 100 cfu/mL. It is a simple, rapid, sensitive, low-cost and easy to be popularized method, which provides a feasible way to monitor E. coli O157: H7 in food safety.
Traditional silicon-based photodetectors are limited by the band gap of silicon, which results in a limited working wavelength range. In this report, due to the excellent properties of Indium Antimonide, the InSb/Si heterojunction photodetectors are fabricated. Under ambient temperature of 280K, as-prepared photodetectors show a specific detectivity of 9.31011 cm Hz1/2/W, responsivity of 54 mA/W, on/off ratio of 5104 under the laser irradiation of 635 nm. In order to explore the influence of working temperature on device performance, the photoresponse at different temperatures was tested. This report proved that as the working temperature increases, the responsivity and specific detectivity of the device decrease, and the performance of the device becomes worse.
In this work, the composite nanofibers of polybutylene terephthalate/polyethylene glycol (PEG/PBT) with difference intrinsic viscosity and different ratio of the hard-segment to the soft-segment were obtained by gas-electrospun. The PEG/PBT-HA composite nanofibers were also obtained by gas-electrospun. PEG/PBT and PEG/PBT-HA composite nanofibers were characterized using scanning electron microscopy (SEM), horizontal attenuated total reflectance for Fourier transformation infra-red spectrometer (HATR-FTIR), dynamic contact angle measurement and differential scanning calorimetry (DSC). The results strongly suggest that this synthetic matrix combines with the advantages of synthetic biodegradable polymers, nanometer-scale dimension mimicking the natural ECM, may represent an ideal tissue engineering scaffold, especially for soft tissue, such as skin and cartilage tissue engineering scaffold.
Quasi-classical trajectory (QCT) method is used to study the stereo-dynamics of the title reaction on the ground 1 1A′ potential energy surface (PES). Differential cross-sections (DCSs) and alignments of the product rotational angular momentum for the reaction are reported. The influence of collision energy on the product vector properties is also studied in the present work. The distribution of angle between k and j′, P(θr), the distribution of dihedral angle denoting k-k′-j′ correlation, P(ϕr) ⋅ (2π/σ)( d σ00/ d ωt), (2π/σ)( d σ20/ d ωt), (2π/σ)( d σ22+/ d ωt) and (2π/σ)(dσ21-/dωt) have been calculated in the center of mass frame, respectively.
One-dimensional (1D) nanowire is one of the most important components for nanosized electronic devices’ development, sensors. Eu3+-doped lanthanum phosphate nanowire has been synthesized via hydrothermal method. The sample is characterized using XRD and SEM; SEM images show the diameter of LaPO4:Eu3+ nanowires before heat treatment is about 10 nm. After sinter, the LaPO4:Eu3+ nanowire becomes particles. The particles grow up and the luminescence intensity becomes lower with the sintering temperature going higher, while the life time of 5D0→7F1 transition is longer. It is suppose that the perfect lattice is not benefit to the dopant ions into.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.