Dual-target photonic detection of extracellular vesicles using core-shell molecularly imprinted particles on zein...

This work presents a novel, sustainable, and flexible biosensing platform with high sensitivity for the dual-target detection of extracellular vesicle surface proteins CD81 and GLAST-1. The platform is constructed using a zein-based film, which is imprinted with channels, sample and detection zones creating a flexible substrate for photonic sensor integration. The system uses the structural color of photonic crystals for visual, label-free detection. Core-shell molecularly imprinted polymer particles, synthesized with a silica core and polydopamine shell, were incorporated into the design to enable selective and sensitive detection of the target peptides through both shifts in reflectance peaks and observable color changes. Two sizes of silica particles were synthesized, generating photonic structures with distinct colors for differentiation between the sensors for CD81 and GLAST-1. The sensors demonstrated excellent performance in human serum matrix, with limits of detection of 3.9 fg mL^-1 for CD81 and 6.2 fg mL^-1 for GLAST-1, highlighting their suitability for diagnostic use. Due to its simplicity, biocompatibility, and scalability, the system shows strong potential for multiplexed detection, while its ability to be miniaturized into integrated microfluidic platforms makes it an alternative to conventional biosensing approaches.