Disposable electrochemical aptasensor for rapid and selective vancomycin detection in clinical samples: Bridging affinity selection, computational modeling and clinical validation.

Antibiotic resistance is a growing global threat, with glycopeptides like vancomycin remaining critical for treating resistant infections. However, its narrow therapeutic index necessitates therapeutic drug monitoring (TDM). In this study, we present a disposable electrochemical aptasensor for cost-effective and rapid vancomycin monitoring. Novel high-affinity aptamers were identified via magnetic bead-based SELEX, with their binding confirmed by surface plasmon resonance and computational modeling. The aptasensor, developed on screen-printed gold electrodes using a multipulse-assisted immobilization method, demonstrated a linear response from 2.5 to 50 μM and a detection limit of 1.5 μM. This range encompasses clinically relevant trough (10-13.5 μM) concentrations. Validated in undiluted clinical samples, it showed performance comparable to gold-standard immunoassays, offering a promising tool for vancomycin TDM.