مشخصات پژوهش

In this study, a highly sensitive and reproducible localized surface plasmon resonance (LSPR)-based sensor was developed for melamine detection using two-dimensional (2D) titanium dioxide (TiO₂) inverse binary colloidal crystals (IBCCs) embedded with gold nanoparticles (AuNPs). IBCCs were fabricated via colloidal lithography with polymethyl methacrylate (PMMA) microspheres (257 nm and 1135 nm) as binary templates. Co-selfassembly at the air–water interface formed 2D binary colloidal crystals (BCC), followed by TiO₂ infiltration and calcination. A 50 nm gold film was deposited via magnetron sputtering, forming AuNPs on and within the pores, enhancing sensitivity by amplifying localized electromagnetic fields. The sensor was functionalized with p-nitroaniline (p-NA) as a melamine receptor and bovine serum albumin (BSA) to block non-specific binding. LSPR peak shifts measured by UV–Vis spectroscopy enabled detection, achieving a 0.005 μg L- 1 limit of detection and 0.015 μg L- 1 limit of quantification. The sensor showed excellent accuracy and selectivity in infant formula and dairy products. The experimental results were confirmed by FDTD simulation.