Simultaneous determination of three food contaminants in shrimp paste by hollow porous pentagonal Au/Ag alloy nanotubes with excellent SERS activity

Herein, we reported a robust and sensitive SERS sensing platform based on hollow porous pentagonal Au/Ag alloy nanotubes (Au/AgANTs) for simultaneous determination of three food contaminants. With the increase amount of etching agent, the morphology of the nanoparticles changed from solid to hollow porous structures, and then the disappearance of pores, accompanied by a trend of first increasing and then decreasing SERS activity. The Au/AgANTs with pentagonal cross section, hollow and pore structure provide stronger local electric field. Under optimized experimental conditions, they were utilized to achieve the simultaneous determination of rhodamine B (RhB), methylene blue (MB) and malachite green (MG) in shrimp paste with low detection limit (5.3 ×10⁻¹¹ M for RhB, 1.27 ×10⁻¹⁰ M for MB and 4.07 ×10⁻¹² M for MG), wide linear detection range (1.0 ×10⁻⁸∼1.0 ×10⁻⁴ M for RhB, 1.0 ×10⁻⁹∼1.0 ×10⁻⁵ M for MB, and 1.0 ×10⁻⁹∼1.0 ×10⁻⁵ M for MG) and satisfactory recoveries (97.24–102.66%), suggesting that the developed method is a promising tool for accurate quantification of the three food contaminants at trace level.