Just-in-time synthesis of FeCo Prussian blue analogue nanozyme for rapid colorimetric immunoassay of α-synuclein toward home-based Parkinson’s disease screening

Abstract

Parkinson’s disease (PD) is a progressive neurodegenerative disorder closely associated with abnormal aggregation of α-synuclein (α-syn). Herein, we developed a just-in-time synthesized FeCo Prussian blue analogue (PBA) nanozyme for rapid colorimetric immunoassay of α-syn. FeCo PBA nanozymes were generated within 15 s at room temperature by directly mixing potassium ferricyanide with Co2+ solution, without hydrothermal treatment or complicated instrumentation. Compared with Fe-based PB, FeCo PBA exhibited superior peroxidase-like activity toward the H2O2-TMB system owing to the synergistic electron transfer between Fe2+/Fe3+ and Co2+/Co3+ redox couples. The obtained nanozyme was subsequently functionalized with detection antibodies to construct a sandwich-type colorimetric immunosensor for α-syn detection. Under optimized conditions, the developed sensing platform produced a rapid visual response within 15 min and exhibited a favorable linear relationship toward α-syn with a low detection limit of 6.17 pg mL-1. Furthermore, the immunosensor demonstrated satisfactory specificity, reproducibility, and recovery performance in serum samples. This work provides a simple and rapid nanozyme-based strategy for portable and home-based PD screening.