The Fabrication of Multiple Stimuli-Responsive Film Electrode and Logic Gates of Rutin

The glassy carbon (GC) electrode surface modified with carboxylic multi-walled carbon nanotubes (c-MWCNTs) and poly (N-isopropylacrylamide) (PNIPAM) films were used to investigate multiple switching electrochemical behaviors of rutin, and a 4-input/3-output logic-gate system was constructed. The drug molecule rutin acted as electroactive probe, and displayed triple stimuli-responsive switchable cyclic voltammetry (CV) properties on c-MWCNTs/PNIPAM film electrodes. From pH 4.0 to pH 9.0 at 25 degrees C, the peak currents of rutin were decreasing with the pH value increasing due to the property of rutin itself and the electrostatic interaction between polyacrylamide (PAA) in the film and rutin molecule. When external temperature and Na2SO4 concentration increased, the CV response signals of rutin decreased because the hydrogen bonds between amide group of PNIPAM hydrogel polymer and water molecules were broken gradually, and a collapsed globule structure was formed. According to above results, multiple stimulus-responsive hydrogel thin film sensor was constructed. Then a 4-input/3-output logic-gate system including AND, NAND and INHIBIT gates was fabricated successfully. The construction of logic-gate system based on drug molecule rutin may provide a novel approach and model leading to design the new-style drug sensor, which might be applied to the intelligent medical diagnostics and drug release. (c) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.