Electrochemical biosensor based on glucose oxidase-coupled cellulose membrane for continuous monitoring of α-amylase in flowing abdominal drainage fluids

Despite the critical role of α-amylase assessment in diagnosing postoperative pancreatic fistula, conventional intermittent testing suffers from inherent delays, overburdened clinical laboratories, and color interference from pigmented drainage fluids. To address these limitations, we present an electrochemical biosensor enabling potential bedside continuous monitoring of α-amylase activity in abdominal drainage fluids from high-risk POPF patients. The system integrates chronoamperometry with a glucose oxidase-functionalized cellulose fiber membrane, a carbon screen-printed electrode, and a microfluidic channel, facilitating continuous, color-immune detection in flowing clinical samples. The sensor exhibited a bilinear range of 100-10000 U/L with a detection limit of 34.7 U/L. To ensure reproducibility, single-point calibration and on-site reconstruction methods were employed to minimize batch-to-batch variability. Finally, preliminary validation using complex, dynamic-flow clinical drainage samples demonstrated reasonable agreement with hospital-reported values, indicating potential clinical utility, though larger cohort studies are warranted to fully establish accuracy and reliability. Overall, this proof-of-concept study demonstrates quantitative α-amylase detection in raw drainage fluid under dynamic flow conditions, representing a step toward continuous monitoring and clinical translation, pending further optimization.