An Antibiofouling Electrochemical Sensor Consisting of Amphiphilic Copolymer on CNT-COOH Electrodes for Point-of-Care Monitoring of Propofol Blood Concentration in Surgical Patients

The monitoring of propofol (PPF) blood concentration is vital for the safety of intravenous anesthesia. Electrochemical sensors represent a powerful tool for the detection of PPF. Our previous research has demonstrated that CNT-COOH electrodes exhibit advantages in resisting electrochemical fouling from PPF oxidation products. Nevertheless, biofouling remains a critical challenge hindering the clinical transformation of PPF electrochemical sensors. To address this issue, we employed in-situ electrodeposition to deposit zwitterionic sulfobetaine methacrylate (SBMA) and overoxidation polydopamine (OPDA) onto CNT-COOH screen-printed electrodes (SPEs) and proposed an innovative CNT-COOH/OPDA-SBMA (CNT-COOH/OPS) amphiphilic antifouling biosensor. This amphiphilic electrode, featuring both hydrophilic and hydrophobic properties, demonstrated excellent antifouling performance through electrochemical characterization in ex-vivo blood assays, coupled with commendable sensitivity, stability, and selectivity. CNT-COOH/OPS SPEs were also applied in point-of-care monitoring of the PPF blood concentrations in animals and clinical surgical patients and exhibited good accuracy and linearity (Ipa=0.0084c+0.4458, R²=0.995) with a limit of detection of 2.948 μM. Further, the electrodes demonstrated a high recovery and the blood concentrations determined by electrochemical detection had robust negative correlation with the depth of anesthesia. Therefore, CNT-COOH/OPS SPEs hold promise as a significant tool in point-of-care monitoring of PPF, offering patients safer and more personalized medical care.