Fabrication of CdTe Quantum Dots-Apoferritin Arrays for Detection of Melamine

Abstract

Melamine has been illegally adulterated in animal feeds and infant formulas to increase the content of crude protein, which results in outbreak of food borne illness such as kidney stones, and renal failure. Accordingly, it is important to detect melamine and its related compounds in foods. In the present work, a method for the detection of melamine by employing two-dimensional (2D) CdTe quantum dots (CdTe QDs)-apoferritin array prepared on modified silicon (Si) surface was proposed. CdTe QDs were synthesized in the cavity of horse spleen apoferritin (HsAFr). The characterization study showed that CdTe QDs were successfully synthesized with average diameters from 1.5 to 3 nm. In addition, when 2D (CdTe QDs)-apoferritin arrays were conjugated with melamine, a significant quenching of the fluorescence was observed. The fluorescence intensity was a linear function of the melamine concentrations up to 2 ppm with a correlation coefficient of 0.9879. Indeed, the CdTe QDs-apoferritin nanodot arrays can be employed as a useful sensing media for melamine detection.