Increasing Toxin Immobilization Efficiency on QCM-Based Immunosensor for Fumonisin

Abstract

Mycotoxins are secondary metabolites of molds, having adverse effects on human and animal health. One of the most important mycotoxins is Fumonisin (FUM), FUM is a common contaminant of corn and corn-based products and may also pose a problem in rice, peanuts and wheat. We have already developed a FUM quartz crystal microbalance (QCM) immunosensor based on inhibitory immunoassay. In this study, it is suggested to increase the efficiency of FUM immobilization and by the way, improve the measurement accuracy. For this purpose, 11-Mercaptoundecanamide (MUD) and 11-Mercaptoundecanol (MUO) were used as an alternative to 11-Mercaptoundecanoic acid (MUA). The reduction of FUM-detection limit (LOD) (0.0669 mg.L-1) indicates an increase of measurement sensitivity by use of MUD agent. In addition to this result, the blocking step has been removed by using of MUO. As conclusion, this study shows that surface modifications seems to reduce sensor sensitivity in situations where orientation is required during immobilization of small molecules.