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

Abstract

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 × 10⁻⁹ M Zn²⁺ with an association constant value of 6.27 × 10⁴ 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.