LAUSR

We herein report the use of melamine and a low-cost screen-printed carbon electrode (SPCE) as the base matrices for the preparation of an electrochemical biosensor. Following the electrochemical polymerization of melamine, the resulting polymelamine was deposited on the SPCE surface to give layers bearing –NH2 functional groups, which allowed the attachment of anti-IgE (immunoglobulin E) antibodies. The resulting anti-IgE-labeled SPCEs were then incubated with IgE solutions of various concentrations prior to analysis by chronoamperometry using Ru(NH3)63+ as an electrochemical mediator. A logarithmic relationship was observed between the chronoamperometric current and the IgE concentration between 5.3 and 530 fM (i. e. over 2 orders of magnitude). In addition, a detection limit of 0.64 fM was achieved in addition to a recovery of 114 ± 14 % for a fetal bovine serum sample spiked with 16 fM IgE. Furthermore, only a small quantity of sample was required for analysis, and the IgE assay was suitable for use in a complex serum matrix without interference. We therefore expect that this novel system will be useful for monitoring the changes in blood IgE levels during the clinical treatment of allergic asthma and rhinitis.