Intelligent luminescent microneedle and hydrogel patches for visual monitoring of lactic acid and dopamine

Dopamine (DA) and lactic acid (LA) are vital biochemical indicators of neurotransmitters and tissue oxidation monitoring, which can comprehensively assess the neurological and physical conditions. The combination of fluorescent sensor and artificial intelligence shows great potentials in monitoring and quantizing of human biochemicals. Herein, a Tb3+ functionalized hydrogen-bonded organic framework material (Tb@ME-TPA) is synthesized based on coordination post-synthesis modification, and its sensing mechanism for DA and LA is investigated by experiments and theoretical calculations. For visual detection of DA and LA in actual environment, Tb@ME-TPA is fabricated into PVA films and microneedle patches, which hold the advantages of high efficiency, sensitivity and anti-interference. In addition, microneedles-based probe for minimally invasive sensing of DA in the dermal interstitial fluid along with a portable smartphone platform are designed to monitor with high accuracy. Furthermore, an intelligent back-propagation neural network model based on fluorescence image recognition is constructed, which can combine optical sensing of LA with deep learning by computer, greatly improving the efficiency and accuracy. This work not only presents a novel idea for the integration of fluorescent materials, smartphones and deep learning, but also provides an effective method for the prediction of diseases as well as the real-time monitoring of overall well-being.