CO probe 1

CO probe 1 (probe 2) is a highly efficient fluorescent CO probe (Ex=493 nm) with an allyl ether reaction site. In the presence of PdCl₂, CO reduces Pd2+ to Pd0, triggering a Tsuji-Trost reaction that removes the allyl protecting group, releases fluorescein, and generates a significant fluorescence signal. CO probe 1 has high selectivity, rapid response (fluorescence enhancement of 150 times within 20 minutes), and low cytotoxicity, and can be used for real-time imaging of CO in living cells. CO probe 1 may be used to study pathological mechanisms involving CO signaling regulation, such as inflammation, vascular disease, or cancer[1].