Molecularly imprinted multilayer nanoparticles for selective detection of kappa-casein Cancer biomarkers: Synthesis, characterisation, and rebinding studies

Abstract

This study reports surface-molecularly imprinted, multilayer core-shell Fe₃O₄ nanoparticles for the selective recognition of kappa-casein, a biomarker of interest in tumour-related diagnostics. Hydroxyl-functionalised Fe₃O₄ nanoparticles were used to immobilise kappa-casein on the particle surface, followed by oxidative polymerisation of aniline to form an imprinted polymer shell. The removal of the template generated surface-accessible binding cavities complementary to kappa-casein. The imprinted nanoparticles showed markedly enhanced selectivity, exhibiting approximately 8-fold and 16-fold higher binding affinities for kappa-casein than for bovine serum albumin and ovalbumin, respectively. A limit of detection of 15 ng mL −1 was achieved, with a distribution coefficient (K d ) of 0.045 mg mL −1 for kappa-casein. These findings demonstrate a practical and sensitive molecular imprinting platform for the selective kappa-casein detection, with potential applications in breast cancer biomarker analysis. • Surface-imprinted Fe₃O₄@PANI nanoparticles for kappa-casein sensing. • Hydroxylated Fe₃O₄ enabled surface immobilisation and imprinting. • Imprinted particles showed 8× and 16× higher kappa-casein affinity. • Sensitive κ-casein detection with a 15 ng mL − 1 detection limit. • Promising platform for selective breast cancer biomarker detection.