Electrochemical immunosensors based on different Au modified dendritic mesoporous silica nanoparticles tag for simultaneous detection of eggs and milk proteinaceous binders used in ancient wall paintings

Abstract

In this study, a label-free and double signal Au modified dendritic mesoporous silica nanoparticles (DMSNs/Au) tag modified electrochemical immunosensor were developed and applied for simultaneously detecting ovalbumin from egg white and casein from milk that are likely to exist in ancient wall paintings. This sensing strategy was designed by introducing two different signals tag based on Au modified DMSNs with porous structure to distinguish corresponding electrochemical signals. The DMSNs with porous structure not only adsorb more electrochemical redox probes, but also immobilize more antibodies, which significantly improved sensitivity of biosensor. Under optimal experiment conditions, the fabricated immunosensor demonstrated excellent performance in the analysis of ovalbumin and casein, with a detection limit of 0.59 ng·mL−1 and 0.36 ng·mL−1, respectively. Finally, the designed sensors were successfully applied to analyze real archaeological samples for evaluating the presence of egg-based, milk-based, or mixed binders in the samples. The proposed immunosensor provides a novel protocol for the analysis and detection of cultural relic materials.