A new fluorescent turn-on probe for the rapid optical sensing of thiols has been designed and synthesized. The probe displays high on/off signal ratios and high selectivity towards thiols. The potential of the probe as a biosensor for thiols was demonstrated by imaging of thiols in living cells.

New functionally diverse urea-derived MOF hydrogen-bond-donating heterogeneous catalysts were achieved via postsynthetic modification, which exhibit excellent catalytic activity and very broad substrate scopes for the Friedel–Crafts alkylation reactions.

In vivo real-time imaging of nitrosative stress in the pathology of stroke has long been a formidable challenge due to both the presence of the blood–brain barrier (BBB) and the elusive nature of reactive nitrogen species, while this task is also informative to gain a molecular level understanding of neurovascular injury caused by nitrosative stress during the stroke episode. Herein, using a physicochemical property-guided probe design strategy in combination with the reaction-based probe design rationale, we have developed an ultrasensitive probe for imaging nitrosative stress evolved in the pathology of stroke. This probe demonstrates an almost zero background fluorescence signal but a maximum 1000-fold fluorescence enhancement in response to peroxynitrite, the nitrosative stress marker. Due to its good physicochemical properties, the probe readily penetrates the BBB after intravenous administration, and quickly accumulates in mice brain to sense local vascular injuries. After accomplishing its imaging mission, the probe is easily metabolized and therefore won't cause safety concerns. These desirable features make the probe competent for the straightforward visualization of nitrosative stress progression in stroke pathology.