Label-Free Immunosensor for the Determination of Microcystin-LR in Water

This paper describes the development of a label-free electrochemical immunosensor based on polyethyleneimine-stabilized magnetite nanoparticles (MGNnP-PEI) for the determination of microcystin-LR (MC-LR). MGNnP-PEI was immobilized on the glassy carbon electrode (GCE) surface and employed as a platform for anchorage of the anti-MC-LR. Hydroquinone in solution was used as a redox probe. After optimization, the immunosensor exhibited a linear response to MC-LR concentrations in the range of 0.1 to 500 ng mL(-1)with a calculated detection limit of 0.053 ng mL(-1). The immunosensor was satisfactorily applied in the quantification of MC-LR in a water sample collected from a freshwater lagoon.