MoS₂/Au/Ag Nanostructures for Ratiometric Surface-Enhanced Raman Scattering Determination of Pesticide Residues

Abstract

Surface-enhanced Raman scattering (SERS) is a promising method for rapid and sensitive detection of pesticide residues. Herein, a three-dimensional MoS2/Au/Ag nanostructure was developed by employing composite systems containing semiconductors, noble metal nanoparticles, and internal standard. The MoS2 nanoflowers provide abundant anchors for the loading of plasmonic nanoparticles so as to generate intense electromagnetic “hot spots,” and the Au-MBN/Ag nanostructures can increase the accuracy of SERS detection with the calibration ability of the internal standard molecules (4-mercaptobenzonitrile, 4-MBN). Therefore, the MoS2/Au/Ag nanostructures integrate the advantages of high-enhancement SERS substrates and high-accuracy ratiometric Raman detection. Moreover, the nanostructures were fabricated via a facile procedure and showed high sensitivity, accuracy, and reproducibility in SERS detection. The nanostructures also showed good linear fitting between the ratios of Raman intensity and logarithmic concentrations of analytes in ratiometric SERS analysis. In addition, thiabendazole (TBZ) in apple juice was successfully detected by using the as-prepared SERS substrates with a limit of detection down to 0.1 ppm in practical applications. To conclude, the MoS2/Au/Ag nanostructures showed excellent SERS activity in ratiometric analysis and the substrate is expected to have great potential for the quantitative detection of low-concentration pesticide residues.

Ultrasensitive and reusable Cu2O/Ag composite SERS substrates for trace thiram detection

“…Combined with the synergistic effect of the electromagnetic enhancement (EM) from NMs and chemical enhancement (CM) of semiconducting materials, high-performance SERS substrates with high activity and good self-cleaning ability can be obtained. [14][15][16][17] Among numerous hybridizing metals and semiconductors, metal oxides are the most popular and commonly used semiconductors. 18 For example, Wang et al proposed a new SERS substrate by depositing Ag nanoflowers (Ag NFs) on ZnO nanorods (ZnO NRs), combining the electromagnetic enhancement of Ag and excellent photocatalytic activity of ZnO NRs to provide the substrate with highly sensitive SERS performance and self-cleaning ability.…”

ReS2 Nanoflowers-Assisted Confined Growth of Gold Nanoparticles for Ultrasensitive and Reliable SERS Sensing

“…Recently, 2D semiconductor SERS substrates such as transition metal dichalcogenides (TMDCs) have been extensively studied and developed [21][22][23][24][25][26][27][28]. Thanks to their large surface area, tunable band gap, good biocompatibility, and easy preparation, TMDCs have emerged as ideal SERS substrates for supporting CM.…”