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.