Carbazole and triazole-containing conjugated polymer as a visual and fluorometric probe for iodide and mercury

A new conjugated polymer containing carbazole and triazole moieties (P1) was successfully synthesized by Suzuki coupling reaction. The UV-vis and fluorescence spectra of the P1 showed significant changes via addition of I− and Hg2+. A colorless P1 solution turned yellow in the presence of iodide salts, which subsequently became colorless again on the addition of Hg2+ salts that could be easily detected visually by the bare eyes. P1 allowed a highly sensitive determination of iodide via significant FL intensity quenching, and fluorescence recovery was observed following the addition of Hg2+. The Stern-Volmer constant (Ksv) value obtained for the detection of iodide was 2.25 × 107 M−1, confirming very high sensitivity of P1 for iodide salts. The detection of both iodide and mercury was also possible in solid state by a P1-based test strip, which showed the capability to detect and respond to both iodide and mercury salts. The results indicated that P1 can act as a dual-channel, high selective, immediacy and sensitive optical probe for I− and Hg2+.