Development and Characterization of Enzymatic Sensors for Real-Time Monitoring of Levodopa

The development of a sensor capable of continuously and in real-time monitoring levodopa concentration marks a crucial advancement toward achieving closed-loop therapy for Parkinson’s Disease. Central to this endeavor is the rigorous benchtop validation and characterization of the sensor. This study elucidates the challenges encountered in creating a continuous, real-time enzymatic sensor for levodopa monitoring, exploring various potentiometric-driven electrochemical sensors employing enzymes capable of direct or quasi-direct electron transfer. Following an initial exploration, specific methods including chronoamperometry, open circuit potential, and transient open circuit potential were utilized to integrate a novel engineered enzyme facilitating direct electron transfer, tailored for levodopa detection. This sensor underwent comprehensive testing to evaluate key clinical aspects such as the impact of interfering compounds, the ability to measure levodopa changes in real-time, and predict both troughs and peaks. Validation was conducted using ex vivo human plasma spiked with levodopa across the therapeutic range, demonstrating exceptional sensitivity. Furthermore, these three electrochemical methods were amalgamated into a single multimodal algorithm, significantly enhancing the sensor's dynamic and linear ranges. This integration showcases the potential for future in vivo application, enabling continuous and real-time monitoring of levodopa, thus advancing the management of Parkinson’s Disease.