Rapid and sensitive label-free SERS determination of fucoxanthin in algae using gold nanoparticles

In this paper, we explored a rapid and ultra-sensitive detection method of fucoxanthin in algae by surface-enhanced Raman scattering. Gold nanoparticles (Au NPs) were prepared by the reduction of chloroauric acid with citric acid. An effective Raman indicator molecule, Rhodamine 6G(R6G) dye molecule, was used to characterize Au NPs that were used in SERS analysis to detect fucoxanthin. It was found that the detection limit of fucoxanthin could reach 10-6 mol.L-1. The characteristic peak of fucoxanthin at a wave number of 1520 cm-1was selected as the working curve, and it presents good linearity of fucoxanthin concentration with R2 = 0.932 in the range from 5x10-4 similar to 1x10-7 M. We first proposed the rapid detection of fucoxanthin by surface-enhanced Raman scattering, which took only one minute to detect. In addition, the Raman strength of the pure algae or kelp and the addition of fucoxanthin was compared under the gold nanoparticle substrate, so as to verify the application value of SERS technology in the rapid determination of fucoxanthin.