1.D.232.  The Bionic TransMembrane NanoChannel (BTM-NC) Family 

A fast and reversibly responsive bionic transmembrane nanochannel for dynamic single-cell quantification of glutathione has been developed (Liu et al. 2023). Some biological channels can rapidly and continuously modulate ion transport behavior in response to external stimuli, which play essential roles in manipulating physiological and pathological processes in cells. To mimic such biological channels, a bionic nanochannel was developed by synergizing a cationic silicon-substituted rhodamine (SiRh) with a glass nanopipette for transmembrane single-cell quantification. Taking the fast and reversible nucleophilic addition reaction between glutathione (GSH) and SiRh, the bionic nanochannel shows a fast and reversible response to GSH, with its inner-surface charges changing between positive and negative charges, leading to a distinct and reversible switch in ionic current rectification (ICR). With the bionic nanochannel, spatiotemporal-resolved operations can be performed to quantify endogenous GSH in a single cell, allowing for monitoring of intracellular GSH fluctuations in tumor cells upon photodynamic therapy and ferroptosis. The results demonstrate that it is a feasible tool for in situ quantification of the endogenous GSH in single cells, which may be adapted to addressing other endogenous biomolecules in single cells by usage of other stimuli-responsive probes (Liu et al. 2023).