Spherical Nanoparticle Arrays with Tunable Nanogaps and Their Hydrophobicity Enhanced Rapid SERS Detection by Localized Concentration of Droplet Evaporation

Abstract

Their properties are usually dependent on morphologies and sizes, and hence the fabrication of controllable uniform micro/nanostructured arrays on a large-scale becomes more important. Conventional methods for obtaining periodical nanostructured arrays are lithographic techniques including laser lithography, [ 26,27 ] electron-beam lithography, [28][29][30] X-ray lithography, [ 31 ] atomic force microscope lithography, [ 32 ] scanning tunneling microscopy technology, [ 33 ] and so on. However, these techniques can not be afforded to most laboratories because of their high processing costs and lower production effi ciency. [ 34 ] In recent decades, with fast development of colloidal science and self-assembly technology, large-scaled monolayer colloidal crystals can be fabricated using highly monodispersed colloidal spheres. [ 35 ] Based on this achievement, another alternative method, colloidal lithography, has been well developed to fabricate multiform periodic micro/nanostructured arrays (i.e., nanoparticle arrays, nanobowl arrays, nanoring arrays, and nanopillar arrays) using these monolayer colloidal crystals as templates or masks [36][37][38][39] by chemical routes including solution-dipping strategy, wet chemical etching, and electrochemical deposition. [40][41][42][43] Such periodic micro/nanostructured array fi lms generally have special rough surfaces, which can be used as SERS-active substrates for detection and identification of organic molecules with trace concentrations. Although chemical routes based on colloidal templates possess advantages of the simple operation, low processing costs, it is still quite diffi cult to achieve micro/nanostructured arrays with very uniform morphology on large-scale by above routes. If these micro/ nanostructured arrays are applied as active substrates in SERS detection, the intensity of SERS spectra in different areas on the sample will fl uctuate in a large range, leading to the failure in practical applications. Whereas other parallel routes, based on physical process method, such as sputtering deposition, pulsed laser deposition, thermal evaporation deposition, atomic layer deposition, and so on, combining with monolayer colloidal crystals template can well resolve these problems. [ 44 ] SERS enhancement activities are mainly dependent on chemical enhancement or local electromagnetic fi eld enhancement at nanoscaled protrusions and cavities. For the latter case, the Periodic hexagonal spherical nanoparticle arrays are fabricated by a sacrificial colloidal monolayer template route by chemical deposition and further physical deposition. The regular network-structured arrays are fi rst templated by colloidal monolayers and then they are changed to novel periodic spherical nanoparticle arrays by further sputtering deposition due to multiple direction deposition and shadow effect between adjacent nanoparticles. The nanogaps between two adjacent spherical nanoparticles can be well tuned by controlling deposition time. Such periodic nanoparticle arrays with gold coatings ...

Special wettable nanostructured copper mesh achieved by a facile hot water treatment process

“…Generally, surfaces with extreme wetting properties, such as superhydrophobic, superhydrophilic, superoleophobic, and superoleophilic surface have been found wide research interests due to their promising applications [13][14][15][16]. Also, surfaces own special wettability, such as superhydrophobic and superoleophilic surfaces, have been arousing inclusive interests due to their looked-for and on-demand applications in oil-water separation [17,18].…”

Bottom-Up Assembly and Applications of Photonic Materials

“…deposition of a material into the interstitial spaces between the spherical particles [62] or the etching of the substrate using the template as a protective mask [63]. Infiltration of a desired material into the template can be done with techniques such as electron beam evaporation [64], electrodeposition [65], sol-gel [66,67], metal evaporation [68,69], and magnetron sputtering [48,70,71]. Either way, at the end of the process when the template is removed, an array of nanoparticles/nanostructures will be produced on the substrate surface.…”

“…Zhang et al described the use of a combination of nanosphere lithography combined with chemical deposition and a subsequent physical deposition step with a careful control of each step to create various types of novel nanostructured arrays resembling honey-combs, hollow cavities and regular network arrays [71,79]. Wang et al reported the use of nanosphere lithography to manufacture titanium dioxide nanobowl structures that were used to further grow titanium dioxide Zhang et al described the use of a combination of nanosphere lithography combined with chemical deposition and a subsequent physical deposition step with a careful control of each step to create various types of novel nanostructured arrays resembling honey-combs, hollow cavities and regular network arrays [71,79]. Wang et al reported the use of nanosphere lithography to manufacture titanium dioxide nanobowl structures that were used to further grow titanium dioxide nanorods in them for photoelectrical water splitting purposes [67].…”

Superhydrophobic 3D Forest‐Like Ag Microball/Nanodendrite Hierarchical Structure as SERS Sensor for Rapid Droplets Detection

“…[17,18] Electrochemical deposition approach was commonly used for fabrication of nanostructures to obtain high catalytic effectiveness on electrodes. [17,18] Electrochemical deposition approach was commonly used for fabrication of nanostructures to obtain high catalytic effectiveness on electrodes.…”

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are dedicated to find a facile and easy way preparing the 3D nanostructures with outstanding SERS performance. [17,18] Electrochemical deposition approach was commonly used for fabrication of nanostructures to obtain high catalytic effectiveness on electrodes. [19,20] It has been considered as a rapid and low-cost method for synthesizing SERS substrates in recent years.

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