- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Light trapping induced flexible wrinkled nanocone SERS substrate for highly sensitive explosive detection
摘要： We reported an ultrasensitive TNT detection method via a novel light trapping induced wrinkled nanocone flexible SERS substrate, which was fabricated by colloidal lithography and oxygen plasma etching on transparent PET film. Especially, a set of nanowrinkles with 50-60nm was found on the sidewall of nanocone after etching. By coating 30nm gold film, this flexible SERS substrate provided uniform hot spots, which demonstrated high reproducibility and sensitivity. 4-ATP molecules based Meisenheimer complex, which is a well-known charge-transfer interaction between electron-poor TNT and electron-rich amino group, was taken to detect ultra-low concentration of TNT explosive. The Raman signal of TNT was significantly enhanced by charge-transfer, light trapping effect and coupled electromagnetic field. The detection sensitivity of TNT molecules was as low as 10-13mol/L, and show a good linear response in the range from 10-8 to 10-13mol/L. Consequently, by brushing this flexible SERS substrate onto a cloth bag, trace amount of TNT residues with concentration as low as 10-10mol/L can be easily analyzed. It is believed that the proposed highly sensitive and uniform flexible substrate provides a significant solution for trace analysis of TNT residue in criminal forensic, military and security check.
关键词： Nanowrinkle,Nanocone,Flexible materials,Light trapping,SERS
更新于2025-09-23 15:21:01
-
Effect of deposition angle on fabrication of plasmonic gold nanocones and nanodiscs
摘要： Metal nanocones can exhibit several strong plasmonic resonances, which are associated with intense and accessible electromagnetic hot spots. They can thus be used to enhance light–matter interactions or to facilitate location-specific sensing while enabling separation of some non-specific contributions towards the sensing signal. Nanocones and similar 3D structures are often fabricated with the use of the so-called self-shading effect, which occurs during the evaporation of a metal film into circular nanowells. Unfortunately, a full description of a successful deposition process with all the essential details is currently missing in literature. Here we present a detailed view of the fabrication of ordered arrays of conical gold nanostructures using electron beam lithography and gold electron beam evaporation. We show that the symmetry of the fabricated nanostructures is influenced by the lateral position of the substrate on the sample holder during the deposition. Off-axis deposition or tilt of the sample leads to asymmetric nanostructures. When the deposited film is thick enough, or the nanowells narrow enough, the entrance aperture is clogged, and nanocones with sharp tips are formed. In contrast, flat-top truncated cones are produced for thinner films or wider nanowells. All these findings help to identify inherent limits for the production of wafer-scale arrays of such non-planar nanostructures. On the other hand, they also suggest new fabrication possibilities for more complicated structures such as mutually connected nanocones for electrically addressable chips.
关键词： Plasmonics,Optical antenna,Nanodisc,Nanocone,Electron beam evaporation,Electron beam lithography
更新于2025-09-23 15:19:57
-
High Broadband Light Transmission for Solar Fuels Production Using Dielectric Optical Waveguides in TiO <sub/>2</sub> Nanocone Arrays
摘要： We describe the fabrication and use of arrays of TiO2 nanocones to yield high optical transmission into semiconductor photoelectrodes covered with high surface loadings of light-absorbing electrocatalysts. Covering over 50% of the surface of a light absorber with an array of high-refractive-index TiO2 nanocones imparted antireflective behavior (< 5% reflectance) to the surface and allowed > 85% transmission of broadband light to the underlying Si, even when thick metal contacts or opaque catalyst coatings were deposited on areas of the light-facing surface that were not directly beneath a nanocone. Three-dimensional full-field electromagnetic simulations for the 400 – 1100 nm spectral range showed that incident broadband illumination couples to multiple waveguide modes in the TiO2 nanocones, reducing interactions of the light with the metal layer. A proof-of-concept experimental demonstration of light-driven water oxidation was performed using a p+n-Si photoanode decorated with an array of TiO2 nanocones additionally having a Ni catalyst layer electrodeposited onto the areas of the p+n-Si surface left uncovered by the TiO2 nanocones. This photoanode produced a light-limited photocurrent density of ~ 28 mA cm-2 under 100 mW cm-2 of simulated Air Mass 1.5 illumination, equivalent to the photocurrent density expected for a bare planar Si surface even though 54% of the front surface of the Si was covered by an ~ 70 nm thick Ni metal layer.
关键词： photovoltaic,nanophotonic,optoelectronic,dielectric nanocone,photoelectrochemical,broadband transmission
更新于2025-09-12 10:27:22
-
A Bioinspired, Highly Transparent Surface with Dry-Style Antifogging, Antifrosting, Antifouling, and Moisture Self-Cleaning Properties
摘要： Transparent coatings with antireflection, antifogging, antifrosting, antifouling, and moisture self-cleaning properties can dramatically improve the efficiency and convenience of optical elements and thus are highly desirable for practical applications. Here, it is demonstrated that a bionic nanocone surface (BNS) fabricated by a facile, low-cost process consisting of template-assisted prepolymer curing followed by surface modification can possess the multiple functions listed above. The polymer coating firmly adheres to a glass substrate due to bonding agents. After SiO2 nanoparticle deposition and low-surface-energy fluorosilane modification, the coating shows low microdroplet adhesion. As a result, the as-prepared BNS exhibits a high transmittance when exposed to fog and good clarity even when the temperature decreases to ?20 °C in a humid environment. Dipping the BNS into exemplified graphite powder has almost no influence on the transparency, and the BNS can realize self-cleaning of moisture when the surface is covered with a thick layer of man-made contaminants.
关键词： dry-style antifogging,bionic nanocone array,antifouling,moisture self-cleaning,antifrosting
更新于2025-09-10 09:29:36