A dual-responsive luminescent sensor for efficient detection of 3-nitrotyrosine and dipicolinic acid biomarkers based on copper(II) organic framework

The trace detection of biomarkers in real samples has profound a most important significance in the early diagnosis and daily monitoring of diseases. Based on the ligand pre-design strategy, a novel 3D CuMOF, with the formula of {[Cu4(BTPB)(mu 2-OH)2(H2O)5]center dot 3H2O}n, was fabricated by using the hexacarboxyl ligand of 1,4-bis(2,4,6-tricarboxylpyrid-5-yl)benzene (H6BTPB) and tetranuclear {Cu4(COO)4(mu 2-OH)2} SBUs. Benefiting from the robust framework and unique luminescence performance, the prepared CuMOF displays great potential as a dual-responsive efficient luminescent sensor in "turn-off" detection of 3-nitrotyrosine (3-NT) biomarker and "turn-on" detecting the anthrax biomarker of dipicolinic acid (DPA), with detection limits (LOD) for 3-NT and DPA being 110.8 ng/ml and 85.2 ng/ml, respectively. Additionally, the practicality and compatibility of such developed sensors were verified by quantifying 3-NT and DPA biomarkers in diluted serum and urine samples with satisfactory recoveries. Further, the theoretical calculations of energy levels as well as the spectral overlap between the analytes and CuMOF were conducted to elucidate the possible sensing mechanisms. This work demonstrated that MOFs-based luminescent sensors are evolving as an efficacious and equable approach for the detection of biomarkers in real samples. Based on ligand pre-design strategy, a chemorobust CuMOF with tetranuclear {Cu4(COO)4(mu 2-OH)2} SBUs based 3D {4.284} lvt net was fabricated and displayed great potential as an efficient dual-responsive luminescent sensor with "turn-off" quenching response to 3-NT, and "turn-on" enhanced luminescence response to DPA in real body fluids. image