A boronate affinity-assisted molecularly imprinted electrochemical sensor based on Ti3C2@AuNPs nanocomposites for the detection of IgG in dairy products.

Abstract

Immunoglobulin G (IgG), a critical immunologically active protein with oral bioavailability, has garnered significant attention as a functional nutrient in the food industry. However, its structural complexity and susceptibility to matrix interference in dairy products pose substantial challenges for rapid and reliable detection. In this study, we developed a novel boronate affinity-assisted molecularly imprinted polymer (MIP) electrochemical sensor by integrating Ti₃C₂ MXene with gold nanoparticles (Ti₃C₂@AuNPs) to enable specific, sensitive, and rapid IgG detection. The incorporation of Ti₃C₂@AuNPs enhanced both the specific surface area and electrical conductivity of the electrode interface, while the boronate affinity-assisted imprinting process generated recognition cavities precisely tailored to the target IgG in terms of size, shape, and chemical functionality, thereby significantly improving sensor sensitivity and selectivity. Comprehensive characterization techniques were employed to validate the structural integrity and electrochemical advantages of the nanocomposite. The optimized sensor exhibited a broad linear detection range (3.2-500 ng/mL, R² = 0.994), an ultralow limit of detection (LOD = 3.2 ng/mL), and enabled accurate quantification of IgG in complex dairy matrices. This work presents a generalizable strategy for the development of next-generation biosensors targeting structurally complex nutrients in functional foods.