GA: A stable coordination polymer (HNU-90-Tb) is synthesized by the assembling of 4-carboxytriphenylamine and Tb³⁺, which exhibits highly selective detection of salicylaldehyde by fluorescence quenching with the limit of detection of 0.07 ppm and response time 30 s. The detection mechanism can be contributed to the internal filtration effect and dynamic quenching.

Salicylaldehyde, an essential chemical intermediate, is extensively utilized in pharmaceutical and fragrance industries. However, the excessive usage leads to environmental pollution and poses potential risks to human body. Hence, it is urgent to develop the effective sensor for the detection of salicylaldehyde (SAL). Herein, a new terbium(III)-based coordination polymer (HNU-90-Tb) is constructed by the assembly of 4-carboxytriphenylamine (HL) with Tb^{3 +}. Benefiting from the hydrophobic structure of HL, HNU-90-Tb exhibits remarkable stability in aqueous environments and is capable of maintaining structural integrity in pH range of 2–11. Notably, HNU-90-Tb enables quantitative detection of SAL through fluorescence quenching, achieving a low detection limit of 0.07 ppm and a rapid response time of just 30 s. HNU-90-Tb also shows excellent selectivity toward a variety of aldehyde analogs. The detection mechanism can be attributed to the combined inner filter effect and dynamic quenching mechanism.