Application of a nanostructured platform and imprinted sol-gel film for determination of chlorogenic acid in food samples

Publication date: 15 August 2016
Source:Talanta, Volumes 156–157
Author(s): Carla M. Ribeiro, Eliane M. Miguel, Jonadab dos S. Silva, Cristian B. da Silva, Marília O.F. Goulart, Lauro T. Kubota, Fabiano B. Gonzaga, Wilney J.R. Santos, Phabyanno R. Lima
Chlorogenic acid (CGA) is a polyphenol derivative that widely exists in higher plants like fruits, vegetables, black teas, and some traditional Chinese medicines. In this work, we have proposed a sensitive and selective electrochemical sensor for detection of CGA. The sensor was based on a glassy carbon electrode (GCE) modified with a functional platform by grafting vinyltrimethoxysilane (VTMS) in multi-walled carbon nanotubes (MWCNTs) and covered by a molecularly imprinted siloxane (MIS) film prepared using the sol-gel process. The VTMS was grafted onto the surface of the MWCNTs via in situ free radical polymerization. The MIS was obtained from the acid-catalyzed hydrolysis/condensation of a solution consisting of tetraethoxysilane (TEOS), phenyltriethoxysilane (PTEOS), (3-aminopropyl)trimethoxysilane (APTMS), and CGA as a template molecule. The modification procedure was evaluated by differential pulse voltammetry (DPV) and scanning electron microscopy (SEM). Under optimized operational conditions, a linear response was obtained covering a concentration ranging from 0.08μmolL⁻¹ to 500μmolL⁻¹ with a detection limit (LOD) of 0.032μmolL⁻¹. The proposed sensor was applied to CGA determination in coffee, tomato, and apple samples with recoveries ranging from 99.3% to 108.6%, showing a promising potential application in food samples. Additionally, the imprinted sensor showed a significantly higher affinity for target CGA than the non-imprinted siloxane (NIS) sensor.

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