Spatiotemporal Visualization of Insecticides and Fungicides within Fruits and Vegetables Using Gold Nanoparticle-Immersed Paper Imprinting Mass Spectrometry Imaging

Abstract

Food safety issues caused by pesticide residue have exerted far-reaching impacts on human daily life, yet the available detection methods normally focus on surface residue rather than pesticide penetration to the internal area of foods. Herein, we demonstrated gold nanoparticle (AuNP)-immersed paper imprinting mass spectrometry imaging (MSI) for monitoring pesticide migration behaviors in various fruits and vegetables (i.e., apple, cucumber, pepper, plum, carrot, and strawberry). By manually stamping food tissues onto AuNP-immersed paper, this method affords the spatiotemporal visualization of insecticides and fungicides within fruits and vegetables, avoiding tedious and time-consuming sample preparation. Using the established MSI platform, we can track the migration of insecticides and fungicides into the inner region of foods. The results revealed that both the octanol-water partition coefficient of pesticides and water content of garden stuffs could influence the discrepancy in the migration speed of pesticides into food kernels. Taken together, this nanopaper imprinting MSI is poised to be a powerful tool because of its simplicity, rapidity, and easy operation, offering the potential to facilitate further applications in food analysis. Moreover, new perspectives are given to provide guidelines for the rational design of novel pesticide candidates, reducing the risk of food safety issues caused by pesticide residue.

Keywords: food safety; gold nanoparticles; mass spectrometry imaging; paper imprinting; pesticides; spatiotemporal visualization.

Figure 1

AuNP-immersed paper imprinting mass spectrometry imaging (MSI) platform and workflow. All fruits and vegetables were imprinted on AuNP-immersed paper using manual stamping for the MSI analysis.

Figure 2

SEM images of original filter paper without AuNP solution immersion at (a) 100,000× and (b) 200,000× magnification, and AuNP-immersed filter paper at (c) 80,000× and (d) 200,000× magnification, respectively.

Figure 3

(a) Optical images and (b) the corresponding MS images of chlorantraniliprole in apple slices without chlorantraniliprole application and with 0, 0.5, 1, 2, and 3 days after chlorantraniliprole spraying. Scale bar of 4 mm.

Figure 4

(a) Optical images and (b) the corresponding MS images of azoxystrobin in strawberry slices 0 h, 12 h, 24 h, and 32 h after being sprayed with azoxystrobin. Scale bar, 3 mm.

Figure 5

MS images of azoxystrobin (a) 0 h, (b) 12 h, (c) 24 h, (d) 48 h, and (e) 96 h after application. MS images of chlorantraniliprole (f) 0 h, (g) 6 h, (h) 12 h, (i) 18 h, and (j) 24 h after application. Scale bar of 5 mm.

Figure 6

(a) Optical images and (b) MS images of pepper slices 0 h and 12 h after the application of chlorantraniliprole and azoxystrobin. Scale bar of 3 mm.