A triphenylamine-based multifunctional fluorescent probe for Cu2+ and Zn2+ as well as mechanochromism and application in latent fingerprints.

In this study, a new versatile fluorescent probe, YH (N, N-((1E, 1'E)-((phenylazanediyl)bis(4, 1-phenylene))bis(methanylylidene))di(picolinohydrazide)), was created and synthesized. YH demonstrated the capability to continuously detect Cu2+ and PO43- in EtOH/HEPES solutions (95/5, V/V, HEPES = 10 mmol, pH = 7.4). Additionally, YH could function as a ratiometric fluorescent probe for identifying Zn2+. The interaction mechanisms among YH and Cu2+ as well as Zn2+ were elucidated through 1H NMR titration, mass spectrometry, and FT-IR spectroscopy. Moreover, YH displayed aggregation-induced luminescence in methanol and water. Furthermore, the solid form of YH exhibited notable mechanochromism characteristics, transitioning from blue to green after grinding, and this process was reversible by ethanol vapor fumigation. Due to YH's high sensitivity to mechanical stimuli, a starch @ YH composite was successfully developed for detecting latent fingerprints. Meanwhile, YH was utilized for detecting Cu2+ and Zn2+ in environmental water samples and was effectively employed with test papers for ion detection, demonstrating broad application prospect.