Sol-gel technology for rapid and selective detection of S. aureus in biomaterial-related infections

• A sol-gel detector material using potassium tellurite as a chromogen was developed. • Material degradation was analysed by EIS and confirmed through colourimetric assays. • Detection of S. aureus is achieved via controlled potassium tellurite release. • The material is specific for S. aureus , detecting the strain within the first 6 h. Catheter-related bloodstream infections (CRBSIs) are a major clinical concern due to their morbidity, mortality, and high healthcare costs. Current diagnostic methods are limited by long incubation times or the need for specialised equipment. To address these limitations, this study proposes the development of a sol-gel-based detection material for the rapid identification of Staphylococcus aureus , a leading causative agent of CRBSIs. The sol-gel matrix incorporates potassium tellurite (K₂TeO₃) as a chromogenic molecule, which undergoes a characteristic black colour change upon reaction with S. aureus . The sol-gel network was optimised to ensure stability, controlled release of tellurite, and strong adhesion to the substrate. Potassium tellurite incorporation was evaluated using ATR-FTIR, 29 Si-NMR, and scanning electron microscopy (SEM). Additionally, degradation kinetics studies in simulated biological fluids were performed by electrochemical impedance spectroscopy (EIS). In vitro assays demonstrated that the material enables S. aureus detection within six hours, linearly correlated with bacterial stationary growth phase. The specificity of the reaction was confirmed using Staphylococcus epidermidis and Pseudomonas aeruginosa , commonly associated with catheter-related infections. The results suggest that this sol-gel-based approach could provide a rapid and reliable diagnostic alternative, potentially facilitating earlier intervention and improving clinical outcomes for patients with CRBSIs.