A new electrochemical sensing approach for lactate analysis: applications in food industry and sports medicine

The accurate monitoring of lactate level is very important in the fields of food quality and sport. In the present work, an effective sensor was introduced for lactate monitoring in food and in human bio-fluid. The non-enzymatic electrochemical sensor was fabricated by bulk modification of a simple carbon paste electrode (CPE) with iron-copper ferricyanide (ICF) catalyst and room temperature ionic liquid (IL). The lactate sensing capabilities of the suggested sensor are significantly enhanced due to the combination of the high conductivity of IL and the improved catalytic properties of the ICF modifier. The chronoamperometric response measurements of the ICF-IL-CPE demonstrated a high sensitivity towards lactate across a broad linear range of 20 to 1000 µM, with a correlation coefficient of R² = 0.999. This sensor also exhibited a detection limit of 4.5 µM, a reproducibility of 3.9% relative standard deviation, and a stability of 95.8% over a period of five weeks. The suggested ICF-IL-CPE depicted minimal background interference against common interfering species. This makes it a highly promising tool for accurately measuring lactate concentrations in various samples including saliva from athletes and cow milk.