High sensitivity chlorogenic acid detection based on multiple layer-by-layer self-assembly films of chitosan and multi-walled carbon nanotubes on a glassy carbon electrode

Abstract

A chlorogenic acid sensor based on a chitosan (CS) and multi-walled carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE) was fabricated via a layer-by-layer (LBL) self-assembly method. The prepared electrode exhibited excellent catalytic performance for chlorogenic redox reactions compared to the bare GCE. The effects of the number assembly layers, scan rate, pH of the supporting electrolyte and accumulation time on chlorogenic acid detection were optimized. Under the optimal conditions, the proposed sensor was significantly sensitive for the detection of chlorogenic acid and showed wide linear detection ranges at low concentrations from 2 × 10⁻⁸ to 1 × 10⁻⁷ mol dm⁻³ and at high concentrations from 1 × 10⁻⁷ to 2.25 × 10⁻⁴ mol dm⁻³. The detection limit was estimated to be 1.16 × 10⁻⁸ mol dm⁻³ (S/N = 3). Furthermore, the chlorogenic acid sensor exhibited excellent selectivity and stability and was utilized in practical applications, in particular, for the determination of human real samples.