Chitosan/Graphene Oxide Nanocomposite-Based Electrochemical Sensor For ppb Level Detection of Melamine

The development of a reliable electrochemical sensor for detecting melamine is crucial given the adverse effect of melamine on the health of humans, especially infants. Here, a chitosan (CS)/graphene oxide (GO) nanocomposite was prepared and used as an electrochemical sensor. The morphology of this nanocomposite was characterized by scanning electron microscopy and transmission electron microscopy, and its structure was investigated using Fourier transform infrared spectroscopy and Raman spectroscopy. Electrochemical experiment results showed that CS/GO nanocomposites exhibit excellent sensing properties to melamine and have an ultrahigh sensitivity of 54.6 μA μM−1 cm−2, a linear range of 4–2300 ppb, and a calculated limit of detection of 0.83 ppb. This material also exhibits positive anti-interference property and fairly accurate measurement in real milk, thus ensuring that the present sensing platform can be utilized for practical applications, such as food inspection.