An innovative dual recognition aptasensor for specific detection of Staphylococcus aureus based on Au/Fe3O4 binary hybrid

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@ Fe3O4). 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 101–107 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.

Advances in deoxyribonucleic acid extraction techniques and point-of-care molecular diagnosis of foodborne pathogens

“…67 Gold (Au) NPs combined with MNPs produce an Au-MNPs nanocomposite which has been extensively employed for DNA extraction as well as sensitive biomolecule detection. 68 Typically, the AuNPs present on the surface of the magnetic nanocomposites readily bind with thiol-attached ssDNA and develop a nanoprobe that can extract the target DNA from the protein-DNA mixture. 69 Thus, Chowdhury et al established a facile DNA separation approach by introducing Au-MNPs as the nanoprobe (Fig.…”

Portable Saliva Sensor Based on Dual Recognition Elements for Detection of Caries Pathogenic Bacteria

“…mutans detection. Electrochemical sensors offer promises for pathogen detection due to their fast response, simple operation, and ease of miniaturization. − With ∼1000 categories of bacteria routinely present in saliva, the distinction of S. mutans from other bacteria is essential to obtain accurate detection results .…”

“…mutans. Aptamers are small single-stranded nucleic acid sequences (DNA), which exhibit much higher long-term stability than antibodies in a wide range of temperature, pH, and ionic strength. ,,− Aptamer–nanozyme interfaces have been fabricated by Tang and co-workers to colorimetrically detect S. mutans in artificial saliva systems .…”

FRET-Based Single-Molecule Detection of Pathogen Protein IsdA Using Computationally Selected Aptamers

“…aureus but they are also not free from limitations. For example, SERS involves significant sample preparation steps and requires intricate fabrication of nanomaterials. , Electrochemical methods offer high-sensitivity detection but their broader application is limited by the need for suitable redox probes. , Nonspecific binding of proteins can also complicate detection using electrochemical methods . With these limitations in mind, the single-molecule fluorescence resonance energy transfer (smFRET) techniques utilizing DNA-based sensors offer opportunities to address some of these challenges due to the flexibility in sensor design and availability of a wide range of donor–acceptor dyes while still offering a high specificity and low pM detection without target amplification. , Most of the methods for the detection of S.…”