A colorimetry-impedance dual-mode ceruloplasmin detection strategy based on dendritic mesoporous silicon nanoparticles with CeO2 encapsulation inside and horseradish peroxidase enrichment outside

The development of methods for highly sensitive and accurate detection of ceruloplasmin (Cp) is of great significance because of the importance of Cp in the diagnosis of Wilson's disease. Herein, we propose a dual-signal amplification colorimetry-impedance dual-mode high-sensitivity Cp detection immunoassay based on CeO2 encapsulation inside and horseradish peroxidase enrichment outside dendritic mesoporous silicon nanoparticles. This CeO2 nanozyme has high catalytic activity, but its activity is affected by the size of the nanoparticles (as the particle size increases and the activity decreases). Dendritic mesoporous silicon nanoparticles (DMSN) encapsulate CeO2, preventing reduction of its catalytic activity due to self-aggregation, and HRP loading on their surfaces achieves (DMSN-Ce-HA) dual signal amplification to obtain high sensitivity. DMSN-Ce-HA, as a bifunctional probe with excellent catalytic activity is used to catalyze the conversion of a chromogenic substrate for colorimetric readout and 4-chloro-1-naphthol to an insoluble precipitation impedance readout, avoiding the tedious assembly of different probes for dual signal production and reducing the uncontrollable factors of in the experiment process. The proposed colorimetric-impedance dual-mode assay provides more accurate, sensitive, and reliable results than traditional single-signal readout analysis and is therefore a promising candidate for biological analysis.