Miniature sono-electrochemical platform enabling effective and gentle electrode biofouling removal for continuous sweat measurements

Developing miniature smart electrochemical sweat sensors to perform continuous and noninvasive health diagnosis at molecule level is in the spotlight. Sensor's biofoulings hinder the targets' approaching, decreasing the detection sensitivity over time and further limiting the accurate analysis. Effective cleaning to remove bio-foulings on electrochemical sensors is a main challenge and needs to overcome urgently for such purpose. We propose a miniature sono-electrochemical platform utilizing submillimeter gigahertz acoustic resonator to effectively clean away the biofoulings and release sensors inherent electrochemical activities. Resonator induced super strong fluid streaming can completely and repeatedly remove sweat biofoulings from gold electrode sur-face, leading to 100% recovery of sensor's activities for continuous reliable measurements. Compared with common sensor renewal strategies, such as acidic or basic solution cleaning, mechanical polishing, traditional low frequency ultrasound treatment, this electrode surface renewal technique is stable, mathematically pre-dictable, effective and gentle so that it does not cause any destructions to inherent electrode surface, and therefore the sensed electrochemical signals on raw and cleaned electrodes are comparable and improvable with no unexpectable deviation. Together with submillimeter size of the resonator, it shows potential to be integrated within wearable electroanalytical microfluidics for developing smart device to carry out continuous health diagnosis.

Automated summary

Developing miniature smart electrochemical sweat sensors for continuous and noninvasive health diagnosis at the molecular level is currently a hot topic. However, the biofoulings on the sensors hinder accurate analysis and require effective cleaning. In this study, a miniature sono-electrochemical platform utilizing a submillimeter gigahertz acoustic resonator was proposed, which effectively removes biofoulings and restores sensor activity.