An innovative dual recognition aptasensor for specific detection of Staphylococcus aureus based on Au/Fe3O4 binary hybrid
Mohamed M. El‐Wekil, Hamada Mohamed Halby, Mahmoud Darweesh, Mohamed E. Ali, Ramadan Ali
Abstract
Abstract Pathogenic bacteria cause disease outbreaks and threaten human health, prompting the research on advanced detection assays. Herein, we developed a selective molecular imprinted aptasensor for sensitive and prompt quantitation of Staphylococcus aureus ( S. aureus ) bacteria. The aptasensor was constructed by immobilization of aptamer on gold nanoparticles modified magnetic nanoparticles (apt-AuNPs@ Fe 3 O 4 ). A functional monomer (o-phenylenediamine, o-phen) was electro-polymerized on the surface of the as-synthesized nanocomposite in the presence of a template ( S. aureus ). After removing S. aureus , the formed imprinted sites were available to extract pathogenic bacteria from complicated matrices. The surface morphology of the as-fabricated nanocomposites was characterized using different spectroscopic and electrochemical methods. Moreover, we thoroughly evaluated factors affecting the synthesis and determination procedures. The molecular imprinted aptasensor exhibited a wide linear range of 10 1 –10 7 CFU mL −1 with a Limit of Detection, LOD (signal to noise = 3) of 1 CFU mL −1 . The aptasensor detected S. aureus in milk, conduit water, and apple juice samples with good recoveries % and satisfactory relative standard deviations (RSDs %) values.