Highly photostable zinc selective molecular marker bearing flexible pivotal unit: opto-fluorescence enhancement effect and imaging applications in living systems

Abstract

Novel molecular probes for imaging zinc in biological systems are gaining interest as they help in understanding the role of zinc in regulating various bio-events. In this regard, a new C2-symmetric molecular system has been developed and successfully applied as light-up material for signaling divalent zinc with green emission. The fluorescence enhancement was highly zinc specific and this newly developed probe L1 bears a submicromolar detection capability. While probe L1 and the ensemble L1-Zn²⁺ exhibited remarkably high photostability, light-triggered fluorescence enhancement was observed in the case of L1-Zn²⁺. The nature of the L1-Zn²⁺ complex and the associated spectral shift are further supported by theoretical calculations. As the present probe absorbs in the visible region and emits in the green, it was preferred as a potential material for imaging zinc in biological systems including animal and plant cells such as pollen grains and fish egg cells. Such fluorescence imaging of zinc revealed the efficacy of the probe in detection and localization of zinc in various biological systems.