Surface-enhanced Raman spectroscopy (SERS) in food analytics: Detection of vitamins B2 and B12 in cereals

Food analysis has been gaining interest throughout recent decades for different reasons: the detection of hazardous substances in food and routine investigations of food composition and vitamin/nutrient contents. Regardless of the targeted component, food analysis raises a few challenges regarding the complexity of the matrix and detecting trace amounts of substances. Rather laborious and time-consuming extraction procedures are needed to develop protocols for the detection and quantification of different components. Following this, different techniques (i.e., microbiological assay, high performance liquid chromatography, HPLC, and surface-enhanced Raman spectroscopy, SERS) are used to further analyze the extracts. We report herein the results obtained regarding the simultaneous detection of two B vitamins (riboflavin, vitamin B2 and cyanocobalamin, vitamin B12) by means of SERS. To achieve the detection of the B vitamins and overcome the above-mentioned analytical challenges, the following three main experimental stages were designed and performed: (i) characterization of the analytes and decision-making regarding the measurement conditions for the SERS experiments, (ii) implementation of a simulated food matrix (based on the composition of the target food product, cereals) for the detection of the vitamins in this matrix and (iii) extraction of the targeted cereal vitamins from samples and optimization of the extraction procedure to simultaneously detect the two B vitamins by SERS.