Core-Shell Au@Ag Nanoparticles as a High-Performance SERS Substrate for Simultaneous Detection of Multiple Fungicides on Mango Surfaces

Description

The above results indicate that the Au@Ag NP substrate, through the synergistic effect of the gold core and silver shell, achieves a combination of high enhancement factor (2.78 × 10⁸), high uniformity (RSD < 5%), and good stability (>60% signal retention after 30 days). In quantitative analysis, the LODs of the three fungicides in standard solutions are all below the national MRLs, and the linear correlation coefficients (R²) are all greater than 0.97, confirming that this substrate is suitable for quantitative analysis of fungicides at trace levels. The experiments on mango surfaces demonstrate that this method can be directly applied to fruit surfaces without complex sample pretreatment, and the mixed-component detection verifies the unique advantage of SERS “fingerprint spectra” for simultaneous multi-residue screening. Regarding data usage, the following recommendations are provided: (1) The calibration curve equations can be used to quantify unknown concentrations, provided that the measurement conditions (laser power, integration time, substrate batch) remain consistent. (2) Since the detection sensitivity on real samples is lower than that in standard solutions, matrix‑matched calibration is recommended for accurate quantification. (3) This method is suitable for rapid on‑site screening; positive results should be further confirmed by complementary techniques such as LC‑MS/MS. (4) Future research could be advanced in two directions: first, immobilizing Au@Ag NPs onto flexible films or chip platforms to develop solid‑state SERS sensors for portable field testing; second, further optimizing the extraction procedure to improve the detection sensitivity in real samples.

Institutions

• Hainan Normal University

  Hainan, Haikou

Categories

Funders

• National Natural Science Foundation of China

  Beijing

  Grant ID: U1704145
• Department of Science and Technology of Hainan Province

  Haikou

  Grant ID: 522MS062
• Hainan Provincial Health Commission

  Haikou

  Grant ID: YSPTZX202207
• the Open Research Fund of the State Key Laboratory of Tropic Ocean Engineering Materials and Materials Evaluation

  Grant ID: STOEM2025KF020

Licence