Evaluation of pistachio aflatoxin (B1) detection by raman and surface enhanced raman spectroscopy (SERS) using two substrates composed of silver nanoparticles

Abstract

In this study, the feasibility of detection of pistachio aflatoxin (B1) using Raman spectroscopy and Surface Enhanced Raman Spectroscopy (SERS) was investigated. for this purpose, the pistachio samples were used in paste form and infected with B1 aflatoxin in concentration of 5 ppb. Raman spectra of healthy and infected pistachio samples were compared. In order to detect aflatoxin B1, the SERS was applied to two types of substrates: Ag nanowires and Ag nanoparticles colloid on glass. The results showed that the detection of 5 ppb concentration of aflatoxin B1 was not feasible. Between the two studied substrates, Ag nanoparticles colloid showed better results to detect aflatoxin B1. Comparing the corresponding peaks of wave numbers of the aflatoxin B1 Raman spectrum (1000 ppb) to the values obtained from computational method (DFT), peaks in 945, 1048, 1148, 1252, 1390, 1527, 1583, 1658 cm-1 were confirmed as the fingerprints of aflatoxin B1 Raman spectrum. We conclude that the Raman spectroscopy has the potential to detect the infection of the aflatoxin B1 in 1000 ppb concentration.

Keywords

• aflatoxin
• ag nanoparticles
• enhanced raman spectroscopy
• pistachio
• substrate