An environmentally sensitive zinc-selective two-photon NIR fluorescent turn-on probe and zinc sensing in stroke

A two-photon near infrared (NIR) fluorescence turn-on sensor with high selectivity and sensitivity for Zn²⁺ detection has been developed. This sensor exhibits a large Stokes' shift (∼300 nm) and can be excited from 900 to 1000 nm, with an emission wavelength of ∼785 nm, making it ideal for imaging in biological tissues. The sensor's high selectivity for Zn²⁺ over other structurally similar cations, such as Cd²⁺, makes it a promising tool for monitoring zinc ion levels in biological systems. Given the high concentration of zinc in thrombi, this sensor could provide a useful tool for in vivo thrombus imaging.