Gold nanoparticle-mediated detection of melamine based on a dual colorimetric and turbidometric readouts

A simple method for rapid detection of melamine in the food is presented. Citrate-coated gold nanoparticles (AuNPs) and cyanuric acid were utilized to generate melamine-concentration dependent colorimetric and turbidometric signals, respectively. As low as 0.4 ppm of melamine can be detected from the whole milk within 15 minutes with this new detection method and a simple acid precipitation based milk pretreatment. This melamine detection method provides a time- and cost- effective alternative to conventional methods.