Selection of High Sensitivity Aptamers as the Binding Molecule Equipage on gFET-Based Aptasensors for the Quantification of Staphylococcus aureus (MRSA)
Methicillin-resistant Staphylococcus aureus (MRSA) remains a major cause of hospital- and community-acquired infections, necessitating rapid and sensitive detection strategies. Here, we report the FluCell-SELEX based generation of MRSA-specific DNA aptamers and their use as high sensitivity binding entities on reduced graphene oxide field-effect transistors (rGO-FET). Six rounds of selection, upon next-generation sequencing delivered five individual aptamers, which were synthesized and biochemically characterized. Two best-performers were then immobilized onto rGO-FETs and the resulting sensors exhibited concentration-dependent changes in source-drain current upon exposure to MRSA with low limits of detection of 3 and 2 cells per mL in PBS buffer and 3 and 11 cells per mL in diluted human serum (10% v/v) for aptamers MRSA_1 and MRSA_5. With these findings and the sensitivity observed we dare to assert that we have added a highly valuable set of MRSA-specific aptamers serving as versatile binding entities on gFETs to the portfolio of available aptasensors against health-relevant bacteria.