Development of an impedimetric immunosensor to determine microycystin-LR. New approaches in the use of electrochemical impedance spectroscopy were used to determine kinetic parameters of immunoreactions

A. DI TOCCO; S. N. ROBLEDO; G. GONZÁLEZ-SAPIENZA; A. DI TOCCO; S. N. ROBLEDO; G. GONZÁLEZ-SAPIENZA; G. LASSABE; H. FERNÁNDEZ; F, J, ARÉVALO; G. LASSABE; H. FERNÁNDEZ; F, J, ARÉVALO; MICAELA M. BOFFADOSSI; MACARENA PÍREZ-SCHIRMER; M. A. ZON; MICAELA M. BOFFADOSSI; MACARENA PÍREZ-SCHIRMER; M. A. ZON

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2020

0013-4686

The development of new electrochemical immunosensors for the detection of environmental contaminants is of great interest due to their simplicity, high sensitivity, and extended analytical range. Because of the antibody is immobilized on the electrode, it is important to determine its loss of reactivity after immobilization. In this work, two aspects were addressed. First, we developed a new methodology based on electrochemical impedance (EI) to determine the kinetic parameters associated with immunoreactions carried out on the electrode. Second, an electrochemical immunosensor based on electrochemicalimpedance spectroscopy (EIE) was developed to determine microcystin-LR in drinking water samples. Microcystin-LR determination was based on a label-free non-competitive immunoassay. The electrochemical immunosensor shows a limit of detection (LOD) of 33 pg mL_1 (3.32 _ 10_11 mol L_1 or 0.033 mg L_1) which is well below the WHO guideline recommendation of 1 mg L_1 and 40 times betterthan the LOD obtained using the same antibody in an optimized conventional competitive ELISA assay. In addition, an acceptable accuracy, with recovery percentages close to 100% were found. The label-free immunosensor is a valuable tool to monitor microcystin-LR in drinking water samples and the environment.