Abstract
Early detection of neurological disorders requires sensitive biosensing platforms capable of quantifying biomarkers at physiologically relevant concentrations. This study presents an electrochemical biosensor utilizing Apt2 aptamer recognition elements for the detection of L-3,4-dihydroxyphenylalanine (L-DOPA), targeting applications in neurological disease monitoring. The sensor design incorporates gold-coated carbon microelectrodes with immobilized aptamer sequences to achieve specific binding toward the target analyte. Performance evaluation across the 50 nM to 1 µM concentration range yielded a linear calibration response with an R² value of 0.935, demonstrating a strong correlation between the electrochemical signal and analyte concentration. The calculated limit of detection reached approximately 20 nM, falling within the nanomolar range, although it exceeded the initial target of <10 nM. Reproducibility assessments revealed an average relative standard deviation of 4.9%, meeting engineering specifications for measurement consistency. Selectivity testing against common interferents revealed moderate cross-reactivity, with competing signals accounting for 18–22% of the equivalent L-DOPA response. Statistical analysis confirmed significant selectivity preference with p = 0.04. Computational modeling, conducted using MATLAB and PyTorch platforms, corroborated the experimental findings, producing simulated calibration curves with an R² value of 0.945. The prototype demonstrates measurable performance characteristics suitable for continued development. While refinement remains necessary to enhance sensitivity and selectivity parameters, the sensor exhibits adequate reproducibility and detection capability within the nanomolar range, suggesting potential utility for neurological disorder monitoring applications.