Differential pulse voltammetry as an analytical tool for raw milk analysis using electrochemical biosensors

Electrochemical sensors and biosensors have great interest in food quality control due to their fast analysis and low prices. However, there are several problems related to the fouling of the electrodes and the preservation conditions that restrict their use in real sample analysis. An alternate method for analyzing complex liquids, such as milk, relies on a multivariate description of the chemical composition of samples based on non-specific fingerprints provided by an array of sensors and the quimiometric analysis of their responses [1-2]. The purpose of this work was to develop an array of biosensors for its application in milk analysis using differential pulse voltammetry (DPV) as the transduction mechanism. In order to develop sensors with enhanced sensitivities and selectivity towards certain molecules, such as galactose and glucose, enzymes were immobilized on the sensors surface resulting in an array of five sensors. Higher sensitivities were achieved in the responses of the biosensors developed showing evident increases on the intensities in presence of the target molecules on standard solutions confirming the correct immobilization of the biomaterial. Furthermore, a first approach on the analysis of raw milk samples was also made by analyzing milks from individual cows to determine differences in their nutritional composition.

[1]Wasilewski T., Kamysz W., Gębicki J. "Bioelectronic tongue: Current status and perspectives" Biosensors and Bioelectronics 150, 2020, 111923. https://doi.org/10.1016/j.bios.2019.111923.

[2] Skládal P. "Smart bioelectronic tongues for food and drinks control" TrAC Trends in Analytical Chemistry 127, 2020, 115887. https://doi.org/10.1016/j.trac.2020.115887.