A Novel Immunosensor Based on Chitosan-Prussian Blue-Graphene Nanocomposite and Au Nanoparticle for Rapid Detection of Melamine

In 2008, serious illnesses and deaths of babies caused by the contaminated powdered infant formula by melamine in China. To determine a rapid detection of melamine in raw milk, an immunosensor based on the chitosan-Prussian blue-graphene nanocomposite and Au nanoparticle was synthesized in this study. Several important parameters of the sensor were optimized and discussed in detail. The optimized concentration of the immobilized antigen and incubation time was 100ng/ml and 40min, respectively. The biosensor exhibits good electrocatalytic behavior to detection of melamine and the linear response range from 0.3 to 1000ng/mL with a correlation coefficient of 0.991 and the detection limit of 0.15ng/mL at the signal to-noise ratio of 3. The immunosensor also has good selectivity, stability and reproducibility. Recoveries of melamine from raw milk samples ranged from 86.0%-103.1%, which was suitable to test the melamine in raw milk samples.