Combining the PeT and ICT mechanisms into one chemosensor for the highly sensitive and selective detection of zinc

A novel fluorescent sensor (ZS1) based on the dual-mechanism of PeT/ICT for the highly sensitive and selective detection of Zn2+ was designed and synthesized. ZS1 displays remarkable selectivity for Zn2+ with an enhanced red-shift in both absorption and emission, which results from the Zn2+-triggered deprotonation of its amide group. ZS1 could detect as low as 7.2 x 10(-9) M Zn2+ with an association constant value of 6.27 x 10(4) M-1. More importantly, it displays specific and sensitive recognition of Zn2+ and especially avoids the interference of Cd2+ in aqueous solution. The probe was also demonstrated to detect Zn2+ in living cells.