Sensors for voltammetric determination of food azo dyes - A critical review

Synthetic azo dyes are currently used for food coloring more frequently than natural ones and the field of their application is very wide. However, many of them can have detrimental effects on living systems and thus the azo dyes content control in food is very important. Voltammetric azo dyes determination offers many advantages, e.g. high sensitivity, selectivity, speed, low investment and running cost, and low laboriousness. Moreover, these methods are robust, reproducible, user friendly, and compatible with the concept of green analytical chemistry. This review is devoted to the critical comparison of electrochemical sensors and measuring protocols used for voltammetric determination of most frequently used azo dyes in food. Attention is focused on the working electrode and its possible modification which is crucial for successful determination.