PREPARATION METHOD FOR VANILLIN RATIOMETRIC ELECTROCHEMICAL APTASENSOR BASED ON NANO-COMPOSITE MODIFIED ELECTRODE

摘要

The present invention specifically relates to a preparation method for a vanillin ratiometric electrochemical aptasensor based on an aptamer/gold nanoparticles/ferrocene/Ketjenblack/ZIF-8 nano-composite modified electrode. The surface of a bare glassy carbon electrode is drop-coated with a ZIF-8 nano-composite doped with errocene and Ketjenblack, the modified electrode is immersed in a chloroauric acid solution, and gold nanoparticles are electrically deposited by means of cyclic voltammetry scanning to prepare a gold nanoparticle-deposited ZIF-8 nano-composite. A vanillin aptamer is linked to the gold nanoparticles by means of an Au-S bond to construct an aptamer-coupled nano-composite sensing platform. An electrochemical curve under different vanillin concentrations is measured, and a linear relationship between the current peak intensity ratio of the vanillin to the ferrocene and the vanillin concentration is fitted to construct the vanillin ratiometric electrochemical aptasensor. Compared with the prior art, the method of the present invention is simple to operate, low in cost, good in ratio signal stability and high in sensitivity, and can be used as a novel ratiometric electrochemical aptasensor for the efficient detection of vanillin.