Measuring vancomycin using paired pulse voltammetry with a wireless instantaneous neurotransmitter concentration sensing system for point-of-care patient treatment

Vancomycin is a glycopeptide antibiotic widely used for severe Gram-positive infections, particularly methicillin-resistant Staphylococcus aureus (MRSA). However, its narrow therapeutic index necessitates precise monitoring to avoid nephrotoxicity, ototoxicity, or hematologic toxicity. Current therapeutic drug monitoring relies on serum assays requiring several hours, delaying timely dose adjustments. Electrochemical approaches such as fast-scan cyclic voltammetry (FSCV) offer potential for real-time bedside monitoring. We used bare AS4 carbon fiber microelectrodes (CFMs) as the vancomycin sensor. The Wireless Instantaneous Neurotransmitter Concentration Sensing (WINCS) Harmoni system, a portable and clinically compatible platform, was used to perform FSCV measurements of vancomycin. Waveform parameters were optimized, and paired-pulse voltammetry (PPV) was applied to enhance detection selectivity in vitro across varying vancomycin concentrations. Two distinct oxidation peaks of vancomycin were observed. PPV analysis indicated that the + 1.44 V peak is predominantly pH-independent, while the + 0.69 V peak demonstrates pH-dependent characteristics. Furthermore, the optimized FSCV waveform yielded a detection limit of 0.36 μM with stable and reproducible signal performance. Paired-pulse FSCV using the WINCS Harmoni platform enables sensitive, real-time electrochemical detection of vancomycin. This approach may support future rapid point-of care monitoring and inform individualized dosing strategies in critical care settings.