Persistent luminescence nanoparticles/hierarchical porous ZIF-8 nanohybrids for autoluminescence-free detection of dopamine

Accurate quantitative detection of biomarkers in complex samples is of remarkable significance for clinical diagnosis and follow-up therapy, which remains challenging due to the severe interference from sample matrix. Herein, a background-free sensing platform toward ultrasensitive dopamine (DA) detection is developed based on a multifunctional nanohybrid by integrating ultrasmall Cr3+-doped zinc gallate (ZnGa2O4:Cr3+, ZGC) persistent luminescence nanoparticles (PLNPs) with hierarchical porous zeolite imidazole framework-8 (HZIF-8). The ZGC PLNPs decorated on the surface of HZIF-8 have long-lasting near-infrared emission and act as signal element, whereas the hierarchically porous HZIF-8 scaffold can serve as an analyte concentrator to enrich DA around ZGC PLNPs. Furthermore, the oxidative polymerization of enriched DA is favored in the alkaline microenvironment provided by 2-methylimidazole in HZIF-8, producing polydopamine (PDA) which finally quenches the luminescence of ZGC/HZIF-8 via photoinduced electron transfer (PET) mechanism. Under the optimized conditions, the proposed nanoplatform exhibits excellent sensitivity and selectivity for the determination of DA in the range of 0.0025-75 mu M with a limit of detection down to 0.0010 mu M. Benefiting from the superior excitation-free persistent luminescence, this platform also shows satisfactory feasibility in quantitative determination of DA in human serum samples. This new strategy can contribute to the development of PLNPsbased biosensors for practical application in clinical analysis.

Automated summary

A background-free sensing platform for ultrasensitive dopamine detection has been developed by integrating persistent luminescence nanoparticles and hierarchical porous zeolite imidazole framework, providing an accurate method for quantitative analysis.