Coffee Ring Fabrication and Its Application in Aflatoxin Detection Based on SERS

The fabrication of a coffee ring was studied in this work to improve its sensitivity in detecting trace analytes based on surface-enhanced Raman scattering (SERS). Gold nanoparticles were synthesized with diameters of similar to 40 nm through the sodium citrate reduction method, and rhodamine 6G (R6G) was employed as a probe to evaluate the performance of the fabricated coffee rings. The results showed that the coffee ring formed from the water-washed gold nanoparticles presented more orderly and regular morphology as well as better SERS properties than the unwashed ones. Furthermore, both the concentration and the amount of gold nanoparticles were found to affect its SERS performance. Using the optimized coffee ring as a SERS substrate, trace R6G with a concentration of 5 x 10(-8) M was detected. This sensing platform could realize aflatoxin B1 (AFB1) detection down to 5 x 10(-7) M and was demonstrated to function well in real-sample testing.

Automated summary

The sensitivity of a coffee ring in detecting trace analytes based on surface-enhanced Raman scattering (SERS) was improved in this study. Gold nanoparticles with diameters around 40 nm were synthesized through the sodium citrate reduction method, and rhodamine 6G (R6G) was used as a probe to evaluate the performance of the fabricated coffee rings. The results showed that the water-washed gold nanoparticles formed a more orderly and regular coffee ring morphology with better SERS properties than the unwashed ones. Moreover, both the concentration and amount of gold nanoparticles affected the SERS performance. Using the optimized coffee ring as a SERS substrate, trace R6G with a concentration of 5 x 10(-8) M was detected. This sensing platform could detect aflatoxin B1 (AFB1) down to 5 x 10(-7) M and performed well in real-sample testing.