Voltammetric sensor for chloramphenicol determination based on a dual signal enhancement strategy with ordered mesoporous carbon@polydopamine and β-cyclodextrin

A simple and sensitive three-dimensional voltammetric sensor was constructed for the determination of chloramphenicol (CAP). First, ordered mesoporous carbon was introduced onto a glassy carbon electrode to improve the electron transport performance, and then a polydopamine layer was formed on the surface to enhance the hydrophilicity and provide a negative charge to attract positively charged CAP. Finally, the electrode surface was modified through electrochemical polymerization with p-cyclodextrin, which contains abundant hydroxygroups to provide more hydrogen-bonding sites for CAP binding. The developed sensor was investigated with square wave voltammetry and cyclic voltammetry, and exhibited a rapid current response and high selectivity for CAP. Under optimal conditions, the method offered a wide current response for CAP from 5.0 x 10(-7) to 5.0 x 10(-4) molL(-1) and the limit of detection was 2.0 10(-7) molL(-1). Milk powder and bee pollen samples spiked with CAP were extracted and then determined using the beta-CD/CMK-3@PDA/GCE sensor with satisfactory recoveries of 80.0%-101.6%. The method was also used to determine CAP residues in real milk and honey samples, and the results correlated well with those obtained using high-performance liquid chromatography. (C) 2017 Elsevier B.V. All rights reserved.