This study aims to evaluate the therapeutic efficacy of Lecanemab in patients with Alzheimer's disease. The researchers will use a novel detection method based on mesoporous gold electrode surface-enhanced electrochemiluminescence (ECL) to monitor specific biomarkers in the patients' plasma. By tracking changes in these biomarkers, the study seeks to determine how effectively Lecanemab treats the disease and to validate this new ECL-based monitoring system as a useful tool for clinical assessment.