N-Unsubstituted-1,2,3-triazole-tethered, AIEE type conjugated polymer as a ratiometric fluorescence probe for silver ions.

A type of N-unsubstituted-1,2,3-triazole-decorated conjugated polymer (P3), with the feature of aggregation-induced emission enhancement (AIEE), was successfully synthesized via a Cu+-catalyzed click reaction between an acetylene-substituted precursor polymer (P2) and azidotrimethylsilane. Except for Ag+, the introduction of other metal ions had only a slight influence on the optical properties of P3. With the introduction of aqueous Ag+, the fluorescence of P3 in a THF–water mixture (vTHF/vwater = 4/1) (buffered with Tris–CA, 1 mM, pH = 7.4) displayed a ratiometric alteration at the blue (∼420 nm) and green (∼495 nm) bands. The corresponding I495/I420 ratio values maintained an upward trend throughout the titration process of Ag+. The detection limit of Ag+ reaches ∼1.4 μM (3σ/k), as evaluated from the corresponding relationship between I495/I420 and [Ag+]. The aggregation between the polymer chains induced by a Ag+–triazole interrelation is the plausible reason for the alteration of P3's optical properties. [ABSTRACT FROM AUTHOR]