A high-field-enhanced nanogap based on a nanoparticle-gold film system and its preparation method

Abstract

The invention provides a high-field-enhanced nanogap based on a nanoparticle-gold film system and a preparation method thereof. The method is as follows: (1) evaporating chromium and gold films sequentially on the surface of the prism; (2) preparing a nano-probe solution; (3) adding the nano-probe solution dropwise on the gold film to form a coupling chip. The prepared nanogap can be used to enhance the detection of Raman spectroscopy, excite the surface plasmons of the gold film by means of prism excitation, and excite the localized surface plasmons between the nanoparticles and their mirror images in the gold film, the nanoparticles The nano-gap between the mirror and the mirror will generate a huge local electric field, and then amplify the Raman signal of the target molecule in the nano-gap to achieve Raman spectral detection with good repeatability and high sensitivity. The method has simple preparation method, low cost and great application potential.

Description

technical field [0001] The invention belongs to the field of spectrum detection, and in particular relates to a method for constructing a high-field-enhanced nano-gap based on a nano-particle-gold film system. Background technique [0002] Traditional surface-enhanced Raman scattering substrates include metal sols and some solid substrates. The preparation of metal sol is simple but unstable, and it is prone to coagulation. When the Raman signal is measured in the solution, the intensity fluctuates greatly, which is generally the result of statistical averaging. For general solid-state substrates, the distribution of "hot spots" is random, difficult to control, and poor in uniformity, which leads to problems such as unstable and poor signals during use, and affects the accuracy and reliability of test data. For some solid substrates prepared by micro-nano processing, the uniformity is better but the cost is expensive, and it is not easy to popularize. Contents of the inve...

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Problems solved by technology

For general solid substrates, the "hot spots" are randomly distributed, difficult to control, and have poor uniformity, which will lead to problems such as unstable signals and poor signals during use, affecting the accuracy and reliability of test data

For some solid substrates prepared by micro-nano processing, the uniformity is better but the cost is expensive, and it is not easy to promote

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