Soft Electronics and Machine Learning for Neurochemical Sensing

Neurotransmitters play essential roles in regulating neural circuit dynamics in both the central nervous system as well as in the peripheral nervous system, including the gastrointestinal tract. Their real-time monitoring offers critical information for understanding neural function and diagnosing disease. However, bioelectronic tools to monitor the dynamics of neurotransmitters in vivo, especially in the enteric nervous system, are underdeveloped. This is mainly due to the limited availability of biosensing tools capable of examining soft, complex, and actively moving organs.

In this talk, I will present our development of NeuroString, a tissue-mimicking, stretchable neurochemical biological interface prepared by laser patterning a metal-complexed polyimide into an interconnected graphene/nanoparticle network embedded in an elastomer. NeuroString sensors allow chronic, in vivo, real-time, multichannel, and multiplexed monoamine sensing in the brain of behaving mice, as well as measuring serotonin dynamics in the gut without undesired stimulation or perturbing peristaltic movements. The described elastic and conformable biosensing interface has broad potential for studying the impact of neurotransmitters on gut microbes and brain–gut communication, and may ultimately be extended to biomolecular sensing in other soft organs across the body. Meanwhile, by leveraging the performance of the graphene-based soft electrochemical sensor and machine-learning–assisted signal processing, we also achieve stable, multiplexed detection of four different monoamine chemicals. Together, these advances open new analytical pathways for decoding gut neurochemistry and its impact on brain function, microbiome interactions, and mental health.