Reversible Chemosensor for Bioimaging and Biosensing of Zn(II) and hpH in Cells, Larval Zebrafish, and Plants with Dual-Channel Fluorescence Signals.

Zinc/Zn(II) is an essential trace element for humans and acts as an important substance that maintains the normal growth, development, and metabolism of the body. Excess or deficient Zn(II) can cause abnormal metabolism in the human body, leading to a series of diseases. Moreover, biosystems have complex homeostasis systems, especially harsh pH (OH-) environments. Thus, investigating the variation in the levels of Zn(II) and OH- is extremely important in clinical, medical, and environmental testing. Nevertheless, the lack of practical and convenient fluorescence imaging tools limits the tracing of Zn(II) and OH- in biosystems. In this work, a well-designed dual-channel fluorescent signal response chemosensor (DACH-fhba) was assembled for selective sensing of Zn(II) and OH- in the biosystem using a fluorescence turn-on strategy. On encountering Zn(II), the chemosensor emitted a blue fluorescence signal (455 nm). Meanwhile, the bright green fluorescence signal (530 nm) increased with OH- addition simultaneously. With the blue/green dual fluorescence response of DACH-fhba, the sensor exhibited high stability and reversibility. Notably, the bioimaging revealed that DACH-fhba successfully tracked Zn(II) and OH- in live cells, larval zebrafish, and plants. Further results implied that DACH-fhba can be used to achieve visual detection of Zn(II) and OH- in organisms. Altogether, this work is conducive to the monitoring of Zn(II) and OH- in organisms and promotes the understanding of the function of Zn(II) and OH- in biosystems.