Simultaneous monitoring of sweat lactate content and sweat secretion rate by wearable remote biosensors

We report on the simultaneous monitoring of sweat lactate concentration and sweat secretion rate. For this aim lactate oxidase-Prussian Blue enzyme-nanozyme type lactate biosensors were elaborated. The use of siloxaneperfluorosulfonated ionomer composite membrane for enzyme-nanozyme immobilization results in the biosensor displaying flux independence in the whole range of physiological sweat secretion rates (0.025-2 mu l cm(-2) min(-1)). On the contrary, current response of the biosensor based on solely siloxane membranes becomes saturated at physiological sweat lactate concentration, depending mostly on the flow rate. Accordingly, for simultaneous monitoring of sweat lactate concentration and its secretion rate both flow-through biosensors were integrated with high-accuracy wearable electronic devices allowing real-time remote monitoring. As found, during exhaustive physical exercise sweat secretion rate and lactate content are independent of each other, thus, confirming that this excretory liquid is suitable for non-invasive diagnostics.

Automated summary

This study reports on the simultaneous monitoring of sweat lactate concentration and sweat secretion rate. By using specific composite membranes and nanoenzymes, lactate biosensors can operate normally at various sweat secretion rates. By combining with wearable electronic devices, real-time remote monitoring can be achieved. This study also found that sweat secretion rate and lactate content are independent of each other during intense physical exercise, indicating the potential of sweat for non-invasive diagnostics.