Shell thickness-controlled synthesis of Au@Ag core-shell nanorods structure for contaminants sensing by SERS

Lan Thi Dang; Huy Le Nguyen; Hai Van Pham; Mai Thi Tuyet Nguyen

doi:10.1088/1361-6528/ac201a

Shell thickness-controlled synthesis of Au@Ag core-shell nanorods structure for contaminants sensing by SERS

Nanotechnology. 2021 Nov 24;33(7). doi: 10.1088/1361-6528/ac201a.

Authors

Lan Thi Dang¹, Huy Le Nguyen¹, Hai Van Pham², Mai Thi Tuyet Nguyen¹

Affiliations

¹ School of Chemical Engineering, Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi, Vietnam.
² Faculty of Physics, Hanoi National University of Education, 136 Xuan Thuy Street, Hanoi, Vietnam.

PMID: 34425570
DOI: 10.1088/1361-6528/ac201a

Abstract

The accessibility of contaminants detection methods is urgently required for environmental and food safety control. In this report, we developed the Au@Ag core-shell nanorod structures for contaminants sensing by surface-enhanced Raman spectroscopy (SERS). The silver shell thickness and the corresponding plasmon wavelength of Au@Ag core-shell nanorods were tuned by changing the coating time and the silver precursor amount. Moreover, these structures exhibit ultra-sensitive detection ability for Nile blue A dye and Fenobucarb pesticide sensing by SERS. Interestingly, the highest Raman enhancement factor is obtained for the Au@Ag core-shell sample with a minimal silver shell thickness leaded by the optimal enhancement of the electromagnetic field of bimetallic structures. Hence, our report demonstrates that the combination of unique features of two plasmonic metals into core-shell structures promises potential applicability in SERS-based analysis.

Keywords: SERS; contaminants; core–shell structure; gold; nanorods; silver.