High-performance donor–acceptor stenhouse adduct sensors with multi-stimuli response for efficient metal ion detection

Abstract

The development of high-performance sensors capable of simultaneously detecting trace metal ions while responding to visible light, heat, and pH changes represents a critical yet challenging frontier in chemical sensing. Addressing this challenge, we designed two novel donor–acceptor stenhouse adducts (DASAs, L-D1 and L-D2) featuring diamine donors with tailored carbon chain lengths, which exhibited multi-stimuli responsive characteristics to visible light, heat, acidity, and alkalinity, particularly, outstanding specificity in metal ion recognition, enabling simple, rapid, and visual detection of metal ions. The prepared L-D1 showed a low detection limit for Cu²⁺ (0.066 μM) and Fe³⁺ (0.11 μM), while the L-D2-derived cyclopentenone isomer (C-D2a) delivered a low detection limit (0.2 μM) for Al³⁺. A mechanism study uncovered that the coordination effect between the metal ions and the two nitrogen atoms at the donor site and the oxygen atom at the acceptor site of DASAs could induce a linear-to-cyclic isomeric transformation of DASA. Based on the above results, high-performance erasable strips and test papers responsive to copper ions and iron ions were developed. The prepared DASAs with versatile switching behavior provide significant opportunities for diverse fields ranging from biosensors to information storage.