Inline potentiometric monitoring of Butyrylcholinesterase activity based on metabolism of bambuterol at the point of care

Globally, millions of patients are being exposed to anesthetics during surgeries. Butyrylcholinesterase (BChE) is the main metabolizing enzyme for these anesthetics. BChE silent activity defect, either acquired or genetic, may be life threatening due to apnea and respiratory paralysis. Hence, the development of point-of-care analytical methods for screening of BChE activity is of great importance to identify patients with BChE defect. This study describes the development of an ionophore-doped screen-printed ion selective electrode as a fast and simple method to efficiently achieve a continuous monitoring of the enzymatic hydrolysis of bambuterol (BAM) as substrate. BChE activity parameters (V-max and K-m) were calculated to be 1.7 x 10(-8) mol min(-1) ml(-1) and 7.9 x 10(-5) mol l(-1), respectively, indicating high affinity of BChE towards BAM. A side by side comparison of the results obtained using the inline potentiometric approach and a recently published online ATR-FTIR method is presented to highlight the opportunities and challenges of each method. For clinical diagnostics, this approach provides a new platform for rapid determination of enzyme kinetics in real time and clearly identify patients that are susceptible to potentially lethal respiratory paralysis.