In vivo monitoring of animal physiological information plays a crucial role in promptly alerting humans to potential diseases in animals and aiding in the exploration of mechanisms underlying human diseases. Currently, implantable electrochemical microsensors have emerged as a prominent area of research. These microsensors not only fulfill the technical requirements for monitoring animal physiological information but also offer an ideal platform for integration. They have been extensively studied for their ability to monitor animal physiological information in a minimally invasive manner, characterized by their bloodless, painless features, and exceptional performance. The development of implantable electrochemical microsensors for in vivo monitoring of animal physiological information has witnessed significant scientific and technological advancements through dedicated efforts. This review commenced with a comprehensive discussion of the construction of microsensors, including the materials utilized and the methods employed for fabrication. Following this, we proceeded to explore the various implantation technologies employed for electrochemical microsensors. In addition, a comprehensive overview was provided of the various applications of implantable electrochemical microsensors, specifically in the monitoring of diseases and the investigation of disease mechanisms. Lastly, a concise conclusion was conducted on the recent advancements and significant obstacles pertaining to the practical implementation of implantable electrochemical microsensors.

Continuous cortisol monitoring (CCM) is essential for stress management, providing physiological insights into psychology and physical health. However, promising platform for CCM urges the design of effective biorecognition moieties and the skin integration of sophisticated functions. Herein, we present a computationally-assisted wearable system for CCM (CWSCCM) that leverages cutting-edge interdisciplinary technologies of in-situ regenerative molecularly imprinted polymers (MIP), signal amplifier organic electrochemical transistor (OECT), iontophoresis-based sweat induction, and microfluidic sweat sampling. The highly integrated system incorporated with OECT biosensor enables in-situ MIP regeneration, and offers continuous approach for cortisol monitoring, with an ultra-low limit of detection of 0.36 nmol/L. We validated the capability of the CWSCCM for long-term cortisol circadian rhythm monitoring in human participants, which shows superior sensitivity, selectivity, and continuous monitoring capabilities. In conclusion, we demonstrated how computational chemistry and OECT technology can extend the capabilities of current wearable CCM, which could potentially advance closed-loop therapeutics applications.

In point‐of‐care diagnostics, the continuous monitoring of sweat constituents provides a window into individual's physiological state. For species like horses, with abundant sweat glands, sweat composition can serve as an early health indicator. Considering the salience of such metrics in the domain of high‐value animal breeding, a sophisticated wearable sensor patch tailored is introduced for the dynamic assessment of equine sweat, offering insights into pH, potassium ion (K⁺), and temperature profiles during episodes of heat stress and under normal physiological conditions. The device integrates a laser‐engraved graphene (LEG) sensing electrode array, a non‐invasive iontophoretic module for stimulated sweat secretion, an adaptable signal processing unit, and an embedded wireless communication framework. Profiting from an admirable Truth Table capable of logical evaluation, the integrated system enabled the early and timely assessment for heat stress, with high accuracy, stability, and reproducibility. The sensor patch has been calibrated to align with the unique dermal and physiological contours of equine anatomy, thereby augmenting its applicability in practical settings. This real‐time analysis tool for equine perspiration stands to revolutionize personalized health management approaches for high‐value animals, marking a significant stride in the integration of smart technologies within the agricultural sector.