Dual-quenching electrochemiluminescence resonance energy transfer system from IRMOF-3 coreaction accelerator enriched nitrogen-doped GQDs to ZnO@Au for sensitive detection of procalcitonin.

• A new ECL-RET donor-receptor was proposed and fabricated for ultrasensitive detection of PCT. • IRMOF-3 not only acted as a carrier for N-GQDs by internal encapsulation and external decoration, but also a coreaction accelerator. • ZnO@Au nanorod was firstly applied as a dual-quenching prober of ECL signal. • The designed immunosensor exhibited low detection limit of 12.58 fg mL−1 for PCT. Herein a novel electrochemiluminescence resonance energy transfer (ECL-RET) pair of isoreticular metal organic framework-3 (IRMOF-3) enriched nitrogen-doped graphene quantum dots (N-GQDs) luminescent material (N-GQDs@IRMOF-3@N-GQDs, donor) and Au nanoparticles modified zinc oxide nanorod (ZnO@Au, acceptor) were firstly designed to fabricate a dual-quenching sandwich-type ECL immunosensor for ultrasensitive analysis of procalcitonin (PCT). IRMOF-3 not only acted as a carrier for abundantly enriching luminescent N-GQDs by internal encapsulation and external decoration, but also a coreaction accelerator which could boost the transformation of persulfate ion S 2 O 8 2− to generate more anion radical SO 4 −, so as to promote the ECL emission of N-GQDs. Additionally, Au nanoparticles were loaded onto the ZnO nanorods through in-situ modification to obtain ZnO@Au, which was firstly applied as a dual-quencher of ECL signal. In the best test environment, a wide detection range from 0.0001 to 100 ng mL−1 was obtained and the limit of detection is 12.58 fg mL−1 (S/N = 3). With excellent reproducibility and sensitivity, the practical test consequence of PCT in human serum samples was satisfactory. These results suggested that this sensing system could provide a reference model for effective detection of disease markers in clinical medicine. [ABSTRACT FROM AUTHOR]