Novel aptasensing strategy for efficiently quantitative analyzing Staphylococcus aureus based on defective copper-based metal-organic framework

We have proposed a novel electrochemical aptasensing strategy for efficiently detecting staphylococcus aureus (S. aureus) based on copper-based metal-organic framework encapsulated with plenty of Cu₂O nanocrystals (represented by ML-Cu₂O@Cu-MOF) synthesized using the mixed ligands of diphenylethyne-3,3',5,5'-tetracarboxylic acid, 1,3,5-benzenetricarboxylic acid, and terephthalic acid. The ML-Cu₂O@Cu-MOF nanospheres comprised multiple Cu valence states (Cu⁰/Cu⁺/Cu²⁺) and Cu₂O nanocrystals, possessed defect-rich crystal structure, high anchoring ability toward aptamer and boosted electrical conductivity. The gained ML-Cu₂O@Cu-MOF-based biosensor exhibited lower limit of detection toward S. aureus, as low as 2.0 and 1.6 CFU mL^-1 within the S. aureus concentration from 10 to 1 × 10⁸ CFU mL^-1 obtained by electrochemical impedance spectroscopy and differential pulse voltammetry techniques, respectively. Additionally, the developed aptasensor also demonstrated high superior stability, excellent reproducibility, acceptable regeneration ability, and wide practicality. The present work can give rise to an alternative aptasensing strategy for analyzing foodborne bacteria or other food containments and ensuring food safety assessment.