We present a concept for large-area, low-cost detection of ultra-high energy cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel Telescopes (FAST), addressing the requirements for the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report first results of a FAST prototype installed at the Telescope Array site, consisting of a single 200 mm photomultiplier tube at the focal plane of a 1 m 2 Fresnel lens system taken from the prototype of the JEM-EUSO experiment. The FAST prototype took data for 19 nights, demonstrating remarkable operational stability. We detected laser shots at distances of several kilometres as well as 16 highly significant UHECR shower candidates.
Novel molecularly imprinted polymers (MIPs) based on the technique of surface-enhanced Raman scattering (SERS) were successfully prepared. Firstly, ZnO nanorods were fabricated with Ag by reduction of Ag on the surface of the ZnO nanorods. Then, ZnO/Ag heterostructures were used as the substrate, rhodamine 6G was used as the template molecule, acrylamide was used as the functional monomer, ethylene glycol dimethacrylate was used as the cross-linker, and 2,2'-azobis(2-methylpropionitrile) was used as the initiator to prepare the ZnO/Ag MIPs (ZOA-MIPs). Through characterization analysis, it was proved that the novel ZOA-MIPs exhibited excellent SERS properties and selectivity. Under the optimal conditions, there was a good linear relationship (R = 0.996) between the Raman signal (at 1654 cm) and the concentration of the templates, and the detection limit was 10 mol L. It was also proved that the ZOA-MIPs had the property of self-cleaning, resulting in good reusability. It is envisaged that the sensitivity of SERS coupled with the selectivity of MIPs could result in a promising chemosensor for practical applications.
In this study, a novel SERS sensor was successfully prepared by combining a molecular imprinted technique (MIT) with a SERS technique to improve the selectivity of the traditional SERS technique. Moreover, a thermo-sensitive technique was also introduced to confer stimuli-responsive properties to the materials. In a typical procedure, the Ag nanoparticles (NPs) were reduced on the surface of ZnO nanorods (NRs), and the ZnO/Ag heterostructures were used as the SERS substrates. Subsequently, a layer of thermo-sensitive imprinted polymer was coated on the surface of ZnO/Ag heterostructures to prepare the thermoresponsive ZnO/Ag/molecularly imprinted polymers (ZOA-TMIPs) by precipitation polymerization. Moreover, it was proven that the ZOA-TMIPs were regenerable and exhibited good reusability. The results proved that the materials in this study can be effectively used for residual organic dye detection in water.
Ag-MIPs were prepared through a multistep procedure, in which MPS and LC were selected as the template molecules. These materials could selectively rebind the templates and could be detected using Raman spectroscopy.
In this study, a novel detection method based on the technique of surface enhanced Raman scattering (SERS) was presented. Firstly, the homogeneous Ag particles were prepared and CdTe quantum dots were modified on the surface of Ag particles to synthesize the Ag/CdTe heterostructures as the SERS substrate. Then 2,6‐DCP was chosen as the template molecule and combined the technique of atom transfer radical polymerization to prepare Ag/CdTe/molecular imprinted polymers (MIPs). Through characterization analysis, it was proved that the Ag/CdTe/MIPs exhibited splendid SERS properties and selectivity. Under the optimal condition, it was presented good linear relationship (R2 = 0.96) between the Raman signal (at 1596 cm−1) and the concentration of the templates, and the detection limit was determined as 10−9 mol L−1. It was envisaged that the sensitivity of SERS coupled with the selective properties of MIPs could induce a promising chemosensor for practical applications.
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