From Dilute to Multiple Layers: Bottom‐Up Self‐Assembly of Rough Gold Nanorods as SERS Platform for Quantitative Detection of Thiram in Soil

Abstract

The nanoparticle density (PD) of the substrates is crucial for surface‐enhanced Raman scattering (SERS) performance. Here, bottom‐up SERS substrates based on rough gold nanorods (R‐Au NRs) with different PD are fabricated and their SERS property are investigated. In particular, R‐Au NRs are deposited on the Si wafer from sparse to dense through electrostatic interaction and from monolayer to multiple layers by interface self‐assembly technique. It is found that the SERS intensity increases dramatically with increasing PD and remains almost unchanged when the PD increases to 241.22 counts µm−2, and the limited penetration depth of laser is the reason for the intensity saturation. Additionally, similar results are observed in the smooth Au NRs substrates, re‐confirming the PD‐dependent SERS performance. Importantly, the SERS activity of R‐Au NRs substrates is higher than smooth Au NRs substrates in each PD, indicating that R‐Au NRs can produce stronger electromagnetic field enhancement, which is supported by the theoretical simulation results. Finally, it is demonstrated that the optimal SERS substrates can be effectively utilized for the quantitative measurement of thiram in soil. Briefly, the PD of substrates has a great impact on SERS activity, which offers an idea for the design of highly efficient SERS substrates.

General approach to surface-accessible plasmonic Pickering emulsions for SERS sensing and interfacial catalysis

“…Figure 5e-g and Supplementary Fig. 16 show the SERS signals of a range of important analyte molecules including drugs (nicotine and panobinostat) 47 , pesticides (thiram) 48 , environmental pollutants (aniline) 49 and food contaminants (naphthalene, biphenyl, pyrene) 50 which can be obtained using CNT-AuNP but not 3-MPA-capped emulsions.…”

Recent Advances in Nanoparticle-Based Optical Sensors for Detection of Pesticide Residues in Soil

“…As particle density increases, the SERS intensity increases dramatically, and rough gold nanorods produce a stronger electromagnetic field enhancement than smooth gold nanorods. Using the optimal SERS substrate, soil thiram can be quantified quantitatively [ 31 ].…”

“…Through feedback inhibition, sulfide ions in the reaction system can inhibit Ag 3 PO 4 catalysis for TMB by sensing chlorpyrifos pesticides [ 50 ]. In addition to enhancing electron transfer between target analytes and electrode surfaces, CuO NPs can also inhibit catalysis by pesticides [ 31 ]. By modifying glassy carbon electrodes with CuO NPs-deposited waste coffee grounds and activated carbon, Mukdasai et al developed a simple and novel enzyme-free electrochemical sensor for the detection of methyl parathion.…”

“…Numerous pieces of research have focused on developing simple and sensitive nanosensors to detect residues of thiram in soil using SERS, absorption spectra, and colorimetric electrochemical spectra. Disulfide bonds have a strong affinity for noble metal NPs; therefore, many experiments have used noble metal NPs as SERS substrates to enhance Raman spectral signals [ 31 , 32 , 33 , 35 , 124 ]. For example, Wang et al [ 34 ] prepared dense gold nanospikes on magnetic microparticles by using AgNPs-modified magnetic microparticles as a template.…”

Layer-by-Layer Assembly of Polystyrene/Ag for a Highly Reproducible SERS Substrate and Its Use for the Detection of Food Contaminants

“…The high sensitivity of SERS is mainly due to the localized surface plasmon resonance (LSPR) of the SERS substrate. Various plasmonic composites were developed and used as SERS substrates [14][15][16][17][18][19][20][21]. The noble metal nanoparticle-functionalized PS microspheres have attracted considerable interest as SERS substrates due to their uniform micrometer size supporting well defined plasmonic nanoparticles on the surface.…”