Detecting toxins in food after 10 minutes thanks to nano silver

Testing on rice, mangoes, oranges, apples, vegetables, tea . nano-silver SERS base can identify pesticides, kill insects.

Scientists at the Institute of Materials Science (Vietnam Academy of Science and Technology) have announced the results of the study of manufacturing SERS substrates with nano-silver structure of leaves and flowers on silicon (Si) to detect Pesticide residues at low concentrations trace from one molecule per million molecules (ppm) to one molecule per billion molecules (ppb).

Silver nanoparticles ([email protected]) deposited on Si surface.

Simply reduce the food extract to the SERS substrate, allow it to dry and run through the Raman spectrometer (surface enhanced scattering signal), based on the Raman peaks and specific analytical calibration curves. of each substance on the scattering spectrum is recorded, scientists can identify what substances are in the food at how much concentration.

Tests on rice, mangoes, oranges, apples, vegetables, tea ., nano-leaf SERS substrates and silver nanoparticles identified pesticides and insecticides of common pyridaben at concentrations of 0.011ppm and 0.014ppm and widely used herbicides in Vietnam are paraquat at concentrations lower than 0.01ppm. Time to obtain Raman spectrum and identify pesticides only 10 - 15 minutes.

The nano silver flowers.(Photo: NVCC).

SERS substrates also analyze toxic substances such as food green dyes, fungicides in aquatic products - malachite green, substances mixed into melamine milk, cyanide poison . at ultra-small concentrations ppb.

According to the research team, product import and export companies, product quality control departments, border-gate customs departments can use SERS soles to check product quality before exporting and importing goods. chemistry, saving time for procedures, reducing congestion in goods for many days, easily causing damage to agricultural products.

After 2 years of implementing research results of the group, the Council of Science and Technology of Vietnam Academy of Science and Technology evaluated excellent acceptance. The results also appear in prestigious international journals such as the Journal of Electronic Materials, the Advanced in Natural Science: Nanoscience and Nanotechnology (ANSN), Internaltional Journal of Nanotechnololy.

Dr. Luong Truc Quynh Ngan, chairman of the research project, said that in the coming time, the group will study the application of SERS method in detecting antibiotic residues in livestock breeding and aquaculture.