An Aggregation-Induced Emissive Platinum(II) Metallacycle as the Energy Donor of Rhodols for Ratiometric Detection of Hydrazine

Industry-produced hydrazine (N₂H₄) is released into the environment, posing a major risk to human health and the ecosystem. Therefore, it is imperative to develop an effective and convenient method for the detection of N₂H₄. Herein, artificial light-harvesting systems (ALHSs) for N₂H₄ detection were constructed by applying an aggregation-induced emission-active platinum(II) metallacycle (<b>TPEMc</b>) as the energy donor and rhodols (<b>P1</b>, <b>P2</b>, and <b>P3</b>) as the energy acceptors. The ratiometric fluorescence probes based on ALHSs for N₂H₄ showed obvious signal amplification and lower limits of detection compared to those of rhodols (<b>P1</b>, <b>P2</b>, <b>P3</b>) alone. The <b>TPEMc</b>-rhodols systems clearly demonstrated a noticeable increase in fluorescence intensity at 550 nm and an obvious fluorescent color shift from cyan to yellow in the presence of N₂H₄. Fascinatingly, N₂H₄ could be visually and quantitatively detected in water by the <b>TPEMc</b>-rhodol systems paired with smartphone RGB analysis. Therefore, the combination of platinum(II) metallacycle with rhodols is a promising strategy for simple, sensitive, and visual detection of N₂H₄.