Multi-branched gold nanostars with fractal structure for SERS detection of the pesticide thiram

The surface-enhanced Raman scattering (SERS) activity of multi-branched gold nanostars with fractal structure has been investigated for trace detection of pesticide thiram . Raman spectrum results show that the gold nanostars substrate can produce about 10 2 fold stronger signal than the thiram alone with the thiram concentration increase of 10 3 times and 1.4 fold stronger signal than the gold nanostars without fractal feature. In the detection procedure, the most prominent SERS peak at 1376   cm −   1 has been chosen to characterize and quantify the concentration of thiram. Experimental results indicate this Raman substrate based on fractal gold nanostars exhibits excellent selective probing performance for thiram with a detection limit as low as 10 −   10   M in solution and 0.24   ng/cm 2 in apple peels. Interference experiment results show that the effects from the interfering pesticides could be neglected in the detection procedure. Therefore, the gold nanostars as a SERS substrate have excellent sensitivity and selectivity.