alkaloid copolymers as fluorimetric INHIBIT and colorimetric AND logic gates for detection of iodide.

Four alkaloid-acrylamide water soluble copolymers with a mean hydrodynamic diameter of 3 nm were synthesised by free radical polymerization. The copolymers were characterised by H NMR, FTIR, GPC, DLS, UV-vis and fluorescence spectroscopy. A blue emission is observed with H switching of 185 and 175-fold for the quinidine and quinine copolymers, and 21 and 11-fold for the cinchonine and cinchonidine copolymers, while the presence of Cl, Br or I causes fluorescence quenching. In emission mode, the copolymers function as fluorescent H, X-driven INHIBIT logic gates (where X = Cl, Br or I). In absorbance mode, the copolymers function as colorimetric H, I-driven AND logic gates in 1 : 1 (v/v) THF/water with a 76-fold enhancement. The solution colour changes from colourless to yellow with formation of new absorbance bands at 288 nm and 353 nm due to a π-anion non-covalent charge transfer interaction. The copolymers may be useful as selective iodide sensors for medical and analytical diagnostics.