A new two-dimensional, spiropyran-based polymer fluorescent nanoprobe with quantitative-fluorescent and photochromic properties for multi-substance detection.

One challenge of the structural design of a fluorescent probe is how to improve the detection performance on trace target analytes in complex samples. Herein a new polymer fluorescent nanoprobe (2DSP-C28) has been synthesized, by adopting a two-dimensional (2D), spiropyran (SP)-based nanosheet structure with hydrophobic long-chain alkanes (C28). Unlike a traditional spiropyran-based small molecule probe, the 2DSP-C28 probe can exhibit quantitative-fluorescent and photochromic properties. Under the detection of metal-ions, the nanoprobe in DMSO aqueous solution is selectively fluorescent-quenched-responsive for Fe-ions (~100 μM), with a characteristic stoichiometric ratio (SR) of <10, a high sensitivity (LOD: ~ 0.2 μM). When the nanoprobe is incorporated into electrospun polyethylene oxide (PEO), it can be used for gas detection, and display a color-change with acid-base gas and identify the HF gas. It is expected that this new polymer fluorescent nanoprobe can be promisingly applied for rapidly environmental monitoring on the ion or gas pollution.