Application of the electrochemical biosensor in the detection of lactose in skimmed milk

Abstract

In this work, an electrochemical approach for the quantitative detection of lactose in skimmed milk was proposed. To this end, a biosensor was developed from the immobilization of the enzyme lactase in the carbon nanotube matrix-carbon paste base. The paste from this association is deposited in the lower cavity of the working electrode, which together with the reference and auxiliary electrodes form the electrochemical cell operated from a potentiostat. The sensitivity and detection limit for lactose was 1.06 µA cm−2 mmol−1 L and 0.15 mmol L−1 respectively and operational stability was observed for 12 h during 10 days of use. The results indicate that the interaction between the lactase enzyme and the NTC favors the detection of lactose through the electrochemical system. The biosensor is easy to manufacture, operate and has a low detection limit and high reliability.