High-efficiency enrichment sers substrate and its preparation method using coffee ring effect

Abstract

The invention provides a high-efficiency enrichment SERS substrate utilizing the coffee ring effect and a preparation method thereof. The substrate is provided with an annular groove, and a layer of water-absorbing layer is filled in the groove, and SERS active substances are permeated and adsorbed on the water-absorbing layer. The middle of the groove is the center of the substrate. The base adopts a double height difference design, the height h1 of the outer edge of the groove is greater than the height h2 of the base center, and the height h2 of the base center is greater than the height h3 of the bottom of the groove. Further, the double composite material is used to optimize the water absorption layer and improve the uniformity in the channel of the groove to reduce the signal fluctuation during the detection process. The invention overcomes the problems of poor uniformity of the SERS substrate, narrow application range, poor controllability, and low sample preparation efficiency in the prior art. Uniformity, expanding the detection area, and improving sample preparation efficiency.

Description

technical field [0001] The invention relates to the field of spectroscopic technology, in particular to a high-efficiency enrichment SERS (Surface Raman Scattering Enhanced) substrate utilizing the coffee ring effect and a preparation method thereof, which can be applied to rapid detection of liquid samples. Background technique [0002] Enhanced sensitivity and signal uniformity are the two most important indicators to determine the performance of SERS substrates, which are related to the accuracy of SERS detection and subsequent result analysis. According to the enhancement mechanism of the SERS effect, under certain conditions, the greater the density of SERS active materials per unit area / volume, the higher the enhancement sensitivity of the substrate; this is one of the most economical strategies to obtain high-sensitivity SERS substrates. In order to increase the density of SERS active substances, some researchers used inorganic salt induction, magnetic field induction...

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Problems solved by technology

However, the former two may have the risk of introducing interfering substances, or the scope of application is narrow, and the latter is difficult to guarantee the droplet deposition shape size, sample preparation efficiency and detection area size, etc.

In addition, these methods greatly sacrificed the uniformity of the substrate while pursuing high sensitivity, resulting in large fluctuations in signal enhancement and unreliable detection results, etc.

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