A portable, low-cost lactate measurement system

Lactate, as a metabolite, plays a significant role in a number of fields, including medical diagnostics, exercise physiology and food science. Traditional methods for lactate measurement often involve expensive and cumbersome instrumentation. This study developed a portable and low-cost lactate measurement system, including independently detectable hardware circuits and user-friendly embedded software, computer, and smartphone applications. The experiment verified that the relative error of the detection current in the device circuit was less than 1%. The electrochemical performance was measured by comparing the [Fe(CN)₆]^3-/[Fe(CN)₆]^4- solution with the desktop electrochemical workstation CHI660E, and a nearly consistent chronoamperometry(CA) curve was obtained. Two modified lactate sensors were used for CA testing of lactate. Within the concentration range of 0.1 mmol·L^-1 to 20 mmol·L^-1, there was a good linear relationship between lactate concentration and steady-state current, with a correlation coefficient (<italic>R</italic>²) greater than 0.99 and good repeatability, demonstrating the reliability of the developed device. The lactate measurement system developed in this study not only provides excellent detection performance and reliability, but also achieves portability and low cost, providing a new solution for lactate measurement.