Self-luminescent europium based metal organic frameworks nanorods as a novel electrochemiluminescence chromophore for sensitive ulinastatin detection in biological samples

In this work, we developed a novel electrochemiluminescence (ECL) biosensor for ulinastatin (UTI) detection based on self-luminescent metal-organic framework (L-MOF) nanomaterials. The L-MOFs could be simply prepared by one-pot methods using Eu3+ and 4,4',4″-s-triazine-1,3,5-triyltri-m-aminobenzoic acid (H3TATAB) as the metallic center and organic ligand, respectively. The Eu-TATAB exhibited high efficiency and stable ECL performance when using K2S2O8 as coreactant. For the established biosensor, Eu-TATAB was both used as the ECL chromophore and protein carrier due to its outstanding biocompatibility and large superficial area, which could load sufficient antibodies to link with antigen in the biosensor for subsequent detection. The established sandwich ECL biosensor showed a wide linear range of 0.1 ng mL-1 - 105 ng mL-1 and a low limit of detection of 9.7 pg mL-1 for UTI detection. In addition, the developed ECL biosensor could also be successfully applied to the real UTI sample determination in serum. The reported biosensor strategy could provide a guide for developing more other novel and promising high-performance ECL nanomaterials, and also be used as a potential method for ultrasensitive UTI detection in disease research.