A multifunctional dicyanoisophorone-based fluorescent probe for Zn and pyrophosphate detection: Practical applications in water, living sprout, and cell imaging.

Zinc ions (Zn) and pyrophosphate (PPi) play pivotal roles in biological systems, with their dynamic concentrations being closely linked to various physiological and pathological processes, making them essential biomarkers for disease diagnosis and health assessment. The development of highly sensitive and selective in situ detection technologies is crucial for elucidating their biological functions. This study introduces an advanced near-infrared fluorescent sensor, DHP, constructed by integrating the molecular framework of dicyanoisophorone (DCI) derivatives with di(thiophen-2-yl)ethyl amide moieties. The probe exhibits significant aggregation-induced emission (AIE) characteristics in tetrahydrofuran/water (THF/HO) mixed systems. Further investigations show that in THF/HEPES (1,1, v/v) buffer systems, DHP specifically recognizes Zn, resulting in a marked emission enhancement at 660 nm (detection limit: 0.13 μM) with a large Stokes shift of 160 nm, effectively minimizing interference from excitation light sources. Moreover, the DHP-Zn complex also serves as a PPi sensor (detection limit: 0.39 μM). The sensing mechanism was investigated via H NMR titration experiments, Fourier transform infrared (FT-IR) spectroscopy, high-resolution mass spectrometry (HRMS) analysis, and density functional theory (DFT) calculations. Furthermore, the probe has been successfully applied in smartphone RGB detection of real water samples, portable swab tests, plant tissue Zn determination, as well as imaging analysis of Zn and PPi in living cells.