Development of an Electrochemical Immunoassay Based on the Use of an Eight‐Electrodes Screen‐Printed Array Coupled with Magnetic Beads for the Detection of Antimicrobial Sulfonamides in Honey

Abstract

In this work an electrochemical immunoassay, based on a direct competitive assay, was developed using magnetic beads as solid phase and carbon screen-printed arrays as transducers for the detection of sulfonamides in food matrices such as honey. Magnetic beads coated with protein A were modified by immobilisation of specific antibodies and then the competition between the target analyte and the corresponding analyte-labelled with an enzyme was carried out; after the immunosensing step, beads were captured by a magnet onto the working surfaces of a screenprinted eight-electrodes array for a multiple electrochemical detection. Screen-printed eight-electrodes arrays were chosen as transducers due to the possibility to repeat multiple analysis and to test different samples simultaneously. Alkaline Phosphatase (AP) was used as enzyme label and Differential Pulse Voltammetry (DPV) as fast electrochemical technique. Calibration curves demonstrate that the developed electrochemical immunoassay was able to detect this class of drugs in standard solutions at low concentrations (ng/mL levels). The short incubation times (25 min) and the fast electrochemical measurement (10 sec) make of these systems a possible alternative to classic ELISA tests. The developed electrochemical immunoassay was coupled to Solid Phase Extraction (SPE) for the analysis of these compounds in a food matrix such as honey.

Electrochemical Sensors in Environmental Analysis

“…52 Another sensor employing a screen-printed eightelectrode-based immunoarray for the detection of sulfonamide antibiotics was developed using magnetic beads as a solid phase, which allowed the rapid extraction of sulfonamides in complex matrices. 53 The combination of the antibody-based assays, magnetic bead separation, and screen-printed array transduction is an attractive aspect of this research that has the potential to be used in the development of a high sample throughput screening system.…”

Electrochemical arrays coupled with magnetic separators for immunochemistry

“…Immunoassays have been widely used for the detection of such molecules. Recently, there has been an increased interest in developing electrochemical immunosensors based on the use of magnetic beads and arrays, in order to obtain very sensitive devices able to carry out the analysis in short times [35][36][37][38][39]. Palleschi's group has developed an immunosensor array, based on a 96-well electrochemical plate coupled with immunomagnetic beads (ELIME array) for detection of an important foodborne pathogens, the Salmonella enterica [38].…”

Recent Biosensors for Food Analysis in Brazil and Italy

“…Another example from Italy dealt with an electrochemical immunoassay, developed using magnetic beads as solid phase and carbon screen-printed arrays as transducers, was developed for the detection of sulfonamides in food matrices (Centi et al 2010). Magnetic beads, coated with protein A, were modified by immobilization of specific antibodies and a competition between the target analyte and the corresponding labeled analyte was carried out.…”