posted on 2024-02-02, 17:04authored byJiahao Liu, Jiahao Lu, Wenliang Ji, Guangwen Lu, Jiao Wang, Tingyan Ye, Yisha Jiang, Juanjuan Zheng, Ping Yu, Nannan Liu, Yanan Jiang, Lanqun Mao
In
vivo sensing of the dynamics of ions with high selectivity
is
essential for gaining molecular insights into numerous physiological
and pathological processes. In this work, we report an ion-selective
micropipette sensor (ISMS) through the integration of functional crown
ether-encapsulated metal–organic frameworks (MOFs) synthesized
in situ within the micropipette tip. The ISMS features distinctive
sodium ion (Na+) conduction and high selectivity toward
Na+ sensing. The selectivity is attributed to the synergistic
effects of subnanoconfined space and the specific coordination of
18-crown-6 toward potassium ions (K+), which largely increase
the steric hindrance and transport resistance for K+ to
pass through the ISMS. Furthermore, the ISMS exhibits high stability
and sensitivity, facilitating real-time monitoring of Na+ dynamics in the living rat brain during spreading of the depression
events process. In light of the diversity of crown ethers and MOFs,
we believe this study paves the way for a nanofluidic platform for
in vivo sensing and neuromorphic electrochemical sensing.