Detection of Staphylococcus Aureus by Aptamer-Gated MCM-41 Nanoparticles

Objective: With their excellent specificity, sensitivity, and speed of detection, aptamer-gated nanoparticles are a potential method for detecting Staphylococcus aureus. These techniques have been effectively used on a variety of actual samples, indicating their promise for real-world uses in environmental monitoring, clinical diagnostics, and food safety. Materials and Methods: MCM-41 nanoparticles were characterized using DLS, SEM and FTIR techniques. Reference strains S. aureus, S. epidermidis, Escherichia coli were used. After the synthesis of fluorescence-loaded silica-coated MCM-41 nanoparticles, fluorescence release experiments were performed using dialysis membrane. Results: The particle size of MCM-41 nanoparticles was determined to be 192±1.782 nm According to BET analysis, the MCM-41 particles had a specific surface area of 1019.37 m2/g, a pore size of 2.42 nm, and a pore volume of 0.99 cm3 g. It was determined that MCM-41 nanoparticles were nano-sized, had a narrow size distribution, and were smooth, amorphous and spherical in shape. MCM-41 nanoparticles were functionalized by amino groups via APTES reaction. FT-IR analysis was performed to determine the correct conjugation. Typical bands at 690 and 1460 nm, which correspond to N-H bending vibrations and N-H asymmetric bending vibrations, respectively, emerged following amino grafting. Fluorescein-loaded silica particles with conjugate aptamer and target bacteria S. aureus showed maximum release. In addition, It was determined that approximately 70% fluorescein release occurred in 6 hours. At detection limits as low as 164 CFU/mL in PBS, rapid and sensitive detection of S. aureus was obtained. Conclusion: The proposed biosensor offers several advantages, including rapid response times, high sensitivity, and specificity for S. aureus detection. Future studies will probably concentrate on increasing the technologies' sensitivity, decreasing detection times, and broadening their range of applications.