Real-time sensing of neurotransmitters by functionalized nanopores embedded in a single live cell

• Main Authors: Xialin Zhang, Linqin Dou, Ming Zhang, Yu Wang, Xin Jiang, Xinqiong Li, Long Wei, Yuejia Chen, Cuisong Zhou, Jia Geng
• Format: Article
• Language: English
• Published: Springer 2021-02-01
• Series: Molecular Biomedicine
• Subjects: Nanopore; Neurotransmitter detection; Artificial synapse; Biosensor
• Online Access: https://doi.org/10.1186/s43556-021-00026-3

Abstract Interface between neuron cells and biomaterials is the key to real-time sensing, transmitting and manipulating of neuron activities, which are the long-term pursue of scientists and gain intense research focus recently. It is of great interest to develop a sensor with exquisite sensitivity and excellent selectivity for real-time monitoring neurotransmitters transport through single live cell. Sensing techniques including electrode-based methods, optogenetics, and nanowire cell penetration systems have been developed to monitor the neuron activities. However, their biocompatibilities remain a challenge. Protein nanopores with membrane compatibility and lumen tunability provide real-time, single-molecule sensitivities for biosensing of DNA, RNA, peptides and small molecules. In this study, an engineered protein nanopore MspA (Mycobacterium smegmatis porin A) through site-directed mutation with histidine selectively bind with Cu2+ in its internal lumen. Chelation of neurotransmitters such as L-glutamate (L-Glu), dopamine (DA) and norepinephrine (NE) with the Cu2+ creates specific current signals, showing different transient current blockade and dwell time in single channel electrophysiological recording. Furthermore, the functionalized M2MspA-N91H nanopores have been embedded in live HEK293T cell membrane for real-time, in situ monitoring of extracellular L-glutamate translocating through the nanopore. This biomimetic neurotransmitter nanopore has provided a new platform for future development of neuron sensors, drug carrier and artificial synapse.