A novel polydopamine electrochemiluminescence organic nanoparticle-based biosensor for parathyroid hormone detection.

In this work, polydopamine electrochemiluminescence (ECL)-organic nanoparticles (EONs) based immunosensing strategy was designed for parathyroid hormone (PTH) detection. Dopamine is oxidized and polymerized to form polydopamine organic nanoparticle via self-polymerization process. Unlike the low photoluminescent efficiency and unsatisfactory fluorescence characters of the fluorescent organic nanoparticles (FONs), the polydopamine EONs do not only show unique physicochemical properties and excellent biocompatibility, but also provide ideal electrochemical properties and bright ECL signals, which can be employed as high-quality ECL luminophores. The ECL-related properties and performance of the EONs are further discussed in this paper. The sensing method has a linear response in the range of 0.05-8 ng/mL with a detection limit of 17 pg/mL. The applicability of this method is evaluated through the determination of PTH in human plasma samples with satisfactory results. To our best knowledge, this was the first time about the exploration of polydopamine organic nanoparticles as ECL luminophores in the biosensing application.