Rapid Detection of Acetamiprid in Foods using Surface-Enhanced Raman Spectroscopy (SERS)

Acetamiprid is a neonicotinoid pesticide that is commonly used in modern farming. Acetamiprid residue in food commodities can be a potential harm to human and has been implicated in the honey bee hive die off crisis. In this study, we developed rapid, simple, and sensitive methods to detect acetamiprid in apple juice and on apple surfaces using surface-enhanced Raman spectroscopy (SERS). No pretreatment of apple juice sample was performed. A simple surface swab method was used to recover acetamiprid from the apple surface. Samples were incubated with silver dendrites for several minutes and SERS spectra were taken directly from the silver surface. Detection of a set of 5 apple juice samples can be done within 10 min. The swab-SERS method took 15 min for a set of 5 samples. Resulting spectral data were analyzed using principal component analysis. The highest acetamiprid peak at 634 cm(-1) was used to detect and quantify the amount of acetamiprid spiked in 1:1 water-methanol solvent, apple juice, and on apple surface. The SERS method was able to successfully detect acetamiprid at 0.5 g/mL (0.5 ppm) in solvent, 3 g/mL (3 ppm) in apple juice, and 0.125 g/cm(2) on apple surfaces. The SERS methods provide simple, rapid, and sensitive ways to detect acetamiprid in beverages and on the surfaces of thick skinned fruits and vegetables. Practical Application We developed rapid, simple, and sensitive methods using surface-enhanced Raman spectroscopy to detect acetamiprid in apple juice and on apple surfaces. These methods require no pretreatment to detect acetamiprid in apple juice and combined a simple swab method to detect acetamiprid on apple surfaces. The methods can be modified to detect acetamiprid and other pesticides or toxins in beverages and on the surfaces of thick-skinned fruits and vegetables.