Ordered polystyrene@gold composite microsphere array with dynamically adjustable and controllable gaps as well as preparation method and application thereof

Abstract

The invention discloses an ordered polystyrene@gold composite microsphere array with dynamically controllable gaps as well as a preparation method and application thereof. The array is a thermotropicshrinkage polyvinyl chloride substrate and an ordered gold composite microsphere array arranged on the thermotropic shrinkage polyvinyl chloride substrate, wherein distance between gold composite microspheres forming the microsphere array is 50-65 nm, the sphere diameters of the microspheres are in a range of 150-935 nm, and the gold composite microspheres are formed by coating the surfaces of polystyrene spheres with gold films. The method comprises the following steps: firstly, placing a single-layer colloidal crystal template formed by polystyrene colloidal spheres on the thermotropic shrinkage polyvinyl chloride substrate; then carrying out plasma etching on the obtained single-layer colloidal crystal template on the thermotropic shrinkage polyvinyl chloride substrate; and depositing the gold films on the obtained single-layer non-close-packed polystyrene sphere template on the thermotropic shrinkage polyvinyl chloride substrate by using a sputter coating method to obtain a targetproduct. The array can be easily and widely commercialized for accurate and repeated detection of a trace amount of a to-be-detected object attached to a surface-enhanced Raman scattering active substrate.

Description

technical field [0001] The invention relates to a microsphere array and its preparation method and use, in particular to an ordered polystyrene@gold composite microsphere array whose gap can be dynamically adjusted and its preparation method and use. Background technique [0002] Surface-enhanced Raman scattering (SERS) spectroscopy, as an ultra-sensitive detection technology, has the advantages of simple operation, rapidity, and fingerprint identification of chemical structures. Has been widely used. For noble metal substrates, the enhancement of Raman signal is mainly attributed to the electromagnetic field enhancement induced by localized surface plasmon resonance on the noble metal surface. When the gap between two noble metal nanostructures is less than 10nm, a very strong coupling electric field will be generated at the gap, which is usually called SERS "hot spot". When the target molecule is in these "hot spots", its Raman signal is significantly amplified, and the ...

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Problems solved by technology

Although this SERS substrate can be used for the detection of trace pollutants, there are deficiencies in both the preparation method and the SERS substrate. First, the shape of the silver nanoparticles on the heat-shrinkable polyvinyl chloride substrate as the SERS substrate The shape, size, gap and distribution are not uniform, so that the gap between the nanoparticles and the arrangement period cannot be precisely adjusted after heating the SERS substrate, and it is difficult to obtain repeatable SERS signals, which affects the accuracy of SERS detection; Secondly, the preparation method cannot obtain nanoparticles with uniform shape and size, uniform gap and uniform distribution of precious metals attached to the heat-shrinkable polyvinyl chloride substrate.

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