A Fast and Reversible Responsive Bionic Transmembrane Nanochannel for Dynamic Single-Cell Quantification of Glutathione

Biological channels can rapidly and continuously modulateion transportbehaviors in response to external stimuli, which play essential rolesin manipulating physiological and pathological processes in cells.Here, to mimic the biological channels, a bionic nanochannel is developedby synergizing a cationic silicon-substituted rhodamine (SiRh) witha glass nanopipette for transmembrane single-cell quantification.Taking the fast and reversible nucleophilic addition reaction betweenglutathione (GSH) and SiRh, the bionic nanochannel shows a fast andreversible response to GSH, with its inner-surface charges changingbetween positive and negative charges, leading to a distinct and reversibleswitch in ionic current rectification (ICR). With the bionic nanochannel,spatiotemporal-resolved operation is performed to quantify endogenousGSH in a single cell, allowing for monitoring of intracellular GSHfluctuation in tumor cells upon photodynamic therapy and ferroptosis.Our results demonstrate that it is a feasible tool for insitu quantification of the endogenous GSH in single cells,which may be adapted to addressing other endogenous biomolecules insingle cells by usage of other stimuli-responsive probes.

Automated summary

Biological channels can modulate ion transport behaviors rapidly and continuously in response to external stimuli, playing important roles in physiological and pathological processes in cells. Researchers have developed a bionic nanochannel by combining a cationic silicon-substituted rhodamine with a glass nanopipette to mimic biological channels for transmembrane single-cell quantification. The bionic nanochannel shows a fast and reversible response to glutathione (GSH), leading to a distinct and reversible switch in ionic current rectification. This tool enables in situ quantification of endogenous GSH in single cells and may be adapted for other endogenous biomolecules.