Specific and ultrasensitive detection of Staphylococcus aureus with a catechol- chitosan redox capacitor based electrochemical aptasensor

The effective and accurate detection of Staphylococcus aureus (S. aureus) is of great importance for quickly treat-ing infected patients, preventing the spread of infection and reducing the formation of resistant strains. This paper describes an electrochemical aptasensor for specific and ultrasensitive detection of S. aureus by combin-ing a redox capacitor amplification system and a specific aptamer. The redox capacitor amplification system was constructed using catechol-chitosan film and 1,10-ferrocene dimethanol (Fc)-hexaammineruthenium (III) chloride (Ru3+) mediators. The aldehyde-modified aptamer was immobilized on the electrode surface by the Schiff base reaction with the amino groups of chitosan and served as a specific biological recognition ele-ment for S. aureus. The proposed electrochemical aptasensor presented great performance in terms of detection time (25 min), linear range (10 -10(8) cfu/mL) and detection limit (2 cfu/mL). The proposed biosensor also displayed good reproducibility and selectivity. The electrochemical apatsensor can quantitatively and directly detect S. aureus in whole blood samples (the spiked recovery rate was 90.5-100.1%), laying the foundation for its clinical application.

Automated summary

This paper describes an electrochemical aptasensor for specific and ultrasensitive detection of Staphylococcus aureus (S. aureus). The sensor combines a redox capacitor amplification system and a specific aptamer to achieve high-performance detection. The proposed sensor has a fast detection time, wide linear range, low detection limit, good reproducibility, and selectivity. It can quantitatively and directly detect S. aureus in whole blood samples, laying the foundation for its clinical application.