Surface Plasma Resonance Biosensing of Phosphorylated Proteins Via Ph-Adjusted Specific Binding of Phosphate Residues with Uio-66

The abnormal phosphorylation of protein is closely relevant to a series of diseases including cancers, neurodegeneration and other immune/inflammatory disorders. But, a simple, accurate and pragmatic methodology for the direct detection of phosphorylation levels of target proteins is still urgent. Herein, a Surface plasma resonance (SPR) biosensor was developed for phosphorylated protein detection based on significant SPR enhancement of UiO-66 and its high affinity with phosphate residues. We further explored to adjust the surface charges of UiO-66 by optimizing the pH of incubation buffer and the NaOH concentration in washing solution to eliminate nonspecific adsorption of nanoparticles on the chip surface. This improved the specificity and sensitivity of the proposed method. Our designed biosensor could distinguished 5% phosphorylated peptides from non-phosphorylated peptides background. Moreover, This SPR-based strategy could directly analyzed the phosphorylation level of target protein in complex extractions from cell lines and tissue samples by integrating target capture, specific recognition of phosphate residues and signal enhancement in one work flow. Thus, this simple and robust biosensor can presented a sensitive, accurate and pragmatic toolbox to detect phosphorylated proteins without complicated procedure and destroying the protein structure, improving the research of phosphoproteomics and clinical diagnosis