Enzymatic construction Au NPs-rGO based MIP electrochemical sensor for adulteration detection of bovine-derived allergen in camel milk.

In this work, a high-performance molecularly imprinted polymer (MIP) sensor for the determination of β-lactoglobulin (β-LG) was fabricated by using trypsin as a template removal reagent. Gold nanoparticles (Au NPs) and reduced graphene oxide (rGO) designed for electrode modification accelerate the heterogeneous electron transfer rate to enhance the sensitivity of the prepared sensor. With enzymatic hydrolysis, β-LG templates were effectively digested into short peptides without damage to the MIP so that the imprinted cavities of the MIP were preserved with a complete spatial structure exhibiting high selectivity. Based on the optimization of the protein removal time and pH, the prepared MIP electrochemical sensor could recognize β-LG in the range of 4-100 ng/mL with a low detection limit (3.58 ng/mL). The sensor also expressed excellent selectivity and was successfully applied to real sample detection. The results demonstrate that the proposed MIP electrochemical sensor may be a promising candidate for camel milk adulteration detection.