Long-term In Vivo Monitoring of Chemicals with Fiber Sensors

Long-term in vivo monitoring of chemicals with implanted sensors has received considerable interests over the past decades owing to their significant contributions in reflecting health conditions and assistance in diagnosing diseases.However,the widely explored chemical sensors outside the body fail to meet the requirements of in vivo applications.This perspective reviews main challenges,recent advances and future directions of long-term in vivo monitoring of chemicals,related to immune response and sensing performance.Challenges in terms of the immune response caused by unstable interfaces between sensors and tissues and improper implanting methods,and the insufficient performance of chemical sensors in complex physiological environment are discussed.Therewith,recent advances in fabricating biocompatible,flexible and thin sensors,developing effective implanting methods with reduced injury and improving the sensitivity,selectivity and stability of chemical sensors for accurate monitoring in vivo are summarized.Finally,we propose the future directions to address these challenges by fiber chemical sensors through the combination of soft fiber configuration,facile implanting methods and new recognition elements,which will provide new platforms for health monitoring and physiological mechanism revealing.