Two Chemorobust Cobalt(II) Organic Frameworks as High Sensitivity and Selectivity Sensors for Efficient Detection of 3-Nitrotyrosine Biomarker in Serum

Rapid detection of the 3-nitrotyrosine (3-NT) biomarker in serum is of great significance in clinical diagnosis and daily disease monitoring. In this work, two chemorobust 3D metal-organic frameworks (MOFs) of [Co(DBrTPA)(NMP)] n (CoMOF-1) and [Co-5(DBrTPA)(4)(DMF)(6)(HCOO)(2)]( n) (CoMOF-2) were fabricated from a halogen-modified ligand of 2,5-dibromoterephthalic (H(2)DBrTPA) and cobalt(II) clusters under solvothermal conditions. The introduction of halogens can improve the stability of the overall framework in different media and pH environments, which also endow two CoMOFs with great potential as luminescent sensors with high sensitivity and selectivity, fast response, good anti-interference, as well as recyclable performance in detecting 3-NT in a PBS buffer solution through quenching effects, with the K sv values being 9.19 x 10(4) M-1 for CoMOF-1 and 1.05 x 10(5) M-1 for CoMOF-2 and the LODs as low as 23.6 ng center dot mL(-1) for CoMOF-1 and 20.1 ng center dot mL(-1) for CoMOF-2. Furthermore, the developed sensors were employed to quantify 3-NT in real serum samples, with satisfactory results. In addition, the possible sensing mechanisms of CoMOFs toward the 3-NT biomarker were also discussed from photoinduced electron transfer and spectral overlaps. This work demonstrated the excellent potential of MOF-based sensors for biomarker detection in serum and provided an outlook to design MOF-based sensors with the help of artificial intelligence and machine learning.