Lab‐on‐paper surface‐enhanced Raman spectroscopy platform based on self‐assembled Au@Ag nanocube monolayer for on‐site detection of thiram in soil

Abstract

A paper-based surface-enhanced Raman spectroscopy (SERS) substrate was prepared by assembling Au@Ag nanocubes onto a patterned paper with the assistance of a mask paper by liquid-liquid interface self-assembly techniques. The paper-based SERS substrate was glued to the glass slide to construct a novel lab-on-paper SERS platform. This paper-based SERS sensor possesses a sample injecting zone together with a SERS detection zone in order that sample pretreatment and detection could be performed simultaneously.The SERS performance of this paper-based sensor was investigated by using 4-MBA as a probe molecule, and its enhancement factor as high as 0.56 × 10 5 could be obtained. Additionally, the SERS sensor demonstrated an excellent repeatability with the relative standard deviation for the variation from the spot-to-spot Raman intensity as low as 12.8%. Based on the superiority and functionality of this paper-based SERS platform, sensitive SERS quantitative analysis of thiram in soil could be achieved, which suggests its significant application prospects for the measurement of pesticides in soil without any pretreatment.

Self-assembly of colloidal nanoparticles into 2D arrays at water–oil interfaces: rational construction of stable SERS substrates with accessible enhancing surfaces and tailored plasmonic response

“…For example, we and other research groups have demonstrated that the interfacial arrays can be transferred onto solid substrates, such as silicon wafers or quartz slides, by sliding the solid substrate material beneath the particles at a tilted angle and then carefully lifting the particle array out horizontally. [85][86][87][88][89][90] Similarly, it has been shown that arrays can be deposited onto the substrate material by placing the substrate at the bottom of the reaction vessel and then draining away the liquid phases. [40,[91][92] The biggest advantage of the physical deposition strategy lies in its versatility, which allows the nanoparticle arrays to be transferred onto almost any type of solid surface with ease, and the way in which the product material can combine the functionalities of both the 2D arrays and the solid substrates.…”

Eco‐Friendly Nanoplatforms for Crop Quality Control, Protection, and Nutrition

“…Wang and co-workers designed a detection platform based on self-assembled Au@Ag nanocube (Au@Ag NCs) using a lab-onpaper SERS strategy for on-site detection of thiram residues in the soil (Figure 2D). [50] Au@Ag NCs with the average size of 53 nm were deposited onto filter paper via liquid-liquid interface self-assembly (LLISA) technology to form a paper-based SERS substrate with the assistance of a mask paper. The experimen-tal results showed that the paper-based SERS substrate exhibited outstanding quantitative ability to detect thiram in the soil, reaching a LOD of 0.148 mg kg −1 (Figure 2E).…”

Filter paper based SERS substrate for the direct detection of analytes in complex matrices

“…Paper-based SERS substrates have previously been prepared by drop-casting colloids onto paper surfaces or by dip-coating paper into colloids. [15][16][17]29,30 However, these methods typically lead to a very non-uniform distribution of nanoparticles on the substrate surface which results in relative standard deviations (RSD) of ca. 60%.…”