Wearable devices for monitoring sweat glucose: an integrated strategy for efficient electrochemical sensors

• We intruduced the physiology of sweat, metabolism of glucose in sweat. • We summarized various sensing devices for detecting glucose in sweat, and the design of diversified electrochemical biosensors. • We discussed the future development potential of an electrochemical sensor-based system for glucose sweat extraction and monitoring. In recent years, sweat, as a biological fluid, has become a reliable proxy for blood analyte concentration, and thanks to wearable devices, in vitro biochemical monitoring has been revolutionized to achieve minimally invasive or even non-invasive measurement. Major technological breakthroughs such as continuous glucose monitoring systems have become commonplace, and devices incorporating sweat stimulation technology enable continuous glucose tracking. In the future, continuous sensing technology, especially the new electrochemical sensing mechanism, will become the focus of research. This article reviews the progress of electrochemical sensors for sweat glucose monitoring, covering the sensing mechanism, sweat production and monitoring sensors. Firstly, the principle, classification, application and role of electrochemical sensor in biological fluid monitoring are introduced. Then the structure of sweat glands, sweat production mechanism, collection methods and detection difficulties were reviewed, and the advantages and disadvantages of common detection methods were analyzed. The application of ampere-ampere, photochemistry, OECT and electroluminescent biosensors in sweat glucose detection is discussed, and the advantages and challenges of various sensors are pointed out, such as ampere-ampere/volt-ampere type has fast response but anti-interference needs to be strengthened, photochemistry does not need external voltage but faces light interference, OECT has low power consumption and high integration but selectivity needs to be improved. Electroluminescence has high sensitivity but complex device. Looking forward to the future, the performance of the sensor will be improved with the development of materials, nanotechnology, and biotechnology, providing a better solution for sweat glucose detection and assisting clinical applications.