Label-free and sensitive impedimetric nanosensor for the detection of cocaine based on a supramolecular complexation with β-cyclodextrin, immobilized on a nanostructured polymer film

摘要: Cocaine, a powerful addictive stimulant drug, has variety of adverse effects on the body, thus its sensitive detection is very important. Here, we report simple, label-free, and impedimetric sensor for determination cocaine based affinity to form an inclusion complex with β-cyclodextrin (β-CD). First, prepared nanostructured poly N-acetylaniline film via electropolymerization monomer glassy carbon electrode (PNAANI/GC), subsequently overoxidized it, conjugated β-CD polymer backbone. The designed synthesized PNAANI serves dual function in sensor: one hand, it maintains high effective surface area geometrically small that significantly enhances number molecules immobilized electrode; other provides upright-oriented conjugation backbone, all receptors are actively involved responding target. Sensitivity was further enhanced by preconcentration modified surface. We attributed changes interfacial charge transfer resistance (R ct) concentration. Under optimized condition (pH 7.4, 5-min accumulation at open circuit voltage), responded concentration range 100 nM–1.0 mM limit 50 nM. Selectivity relative some potential inferring compounds also investigated, results were promising. proposed approach exhibited extended dynamic range, low limit, good sensitivity, desirable selectivity, which efficient application prospect on-field sensing.