Biological thiols, including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play important roles in maintaining the appropriate redox status of biological systems. The discrimination between them is of great importance because of their different biological roles. Herein, we present a new near-infrared (NIR) fluorescent sensor Cy-NO2 for selective detection of Cys over Hcy/GSH. The nitrothiophenol group is introduced to quench the fluorescence through photo-induced electron transfer (PET). The sensor undergoes displacement of nitrothiophenol with thiol to turn on the fluorescence. The amino groups of Cys/Hcy further replace the thiolate to form amino-substituted products, which exhibit dramatically different photophysical properties compared to the sulfur-substituted product from the reaction with GSH. By means of more rapid intramolecular displacement of sulfur with the amino group of Cys than Hcy, the discrimination of Cys is achieved. Moreover, Cy-NO2 was successfully applied for bioimaging Cys in living cells.
Intrinsically stretchable electronics have gained extensive interest recently, due to their promising application in wearable electronics, bio‐integrated electronics, and healthcare devices. All of the components of such stretchable electronics need to be stretchable and mechanically robust to accommodate complex movements. The design and fabrication of robust intrinsically stretchable electronic materials represent a critical challenge in this emerging field. In this review, we focus on the latest studies of intrinsically stretchable electronics, covering the strategies for achieving intrinsically stretchable electronic materials, the recent progresses in the key electronic materials including intrinsically stretchable conductors, semiconductors, dielectrics, and the devices produced by them. Finally, some suggestions and prospects for the future development of intrinsically stretchable electronics are proposed.