本研究旨在開發一種具備高靈敏度與高穩定性的「螢光開啟式 (Turn-on)」適體感測器 ( aptasensor )，以解決傳統阿茲海默症關鍵生物標記物 β-澱粉樣蛋白寡聚體 ( Aβ oligomers ) 檢測方法中面臨的背景干擾高與成本昂貴等侷限。在感測機制的設計上，本研究成功利用微波法合成碳點 ( carbon dots， CD ) 作為螢光訊號源，並結合金奈米粒子 ( AuNPs ) 作為高效的螢光適體感測器。而當高神經毒性的 Aβ 寡聚體存在時，適體與其發生特異性結合，引發結構改變並促使 CD螢光訊號提升，藉由量測此螢光訊號的變化即可達到定量分析的目的。 實驗結果顯示，在最佳化反應條件下，該感測平台對 Aβ 寡聚體展現出極佳的檢測靈敏度，其檢測極限( limit of detection )可低達 88 fM。此外，透過加入多種血液干擾物、不同型態的 Aβ (單體與纖維體) 以及在人類血清環境中進行測試，證實該感測器具有優異的專一性與抗干擾能力。總結而言，本研究所建構之 CD/AuNPs 適體感測器，成功克服了傳統檢測中成本高且檢測極限不夠低的問題，具有低成本、操作簡便且低檢測極限等優勢，為阿茲海默症的早期診斷提供了深具潛力的新型策略。;This study aims to develop a highly sensitive and stable "turn-on" aptasensor to overcome the limitations of traditional methods for detecting β-amyloid oligomers， a key biomarker for Alzheimer′s disease， such as high background interference and high cost. In terms of sensing mechanism design， this study successfully utilized microwave-synthesized carbon dotsas a fluorescence signal source and combined them with gold nanoparticles as a highly efficient fluorescent aptasensor. When highly neurotoxic Aβ oligomers are present， the aptasensor specifically binds to them， inducing structural changes and enhancing the CD fluorescence signal. Quantitative analysis can be achieved by measuring this change in fluorescence signal. Experimental results show that， under optimized reaction conditions， this sensing platform exhibits excellent detection sensitivity for Aβ oligomers， with a detection limit as low as 88 fM. Furthermore， testing with various blood interfering agents， different forms of Aβ ( monomers and fibrils )， and in a human serum environment confirms the sensor′s excellent specificity and anti-interference capabilities. In summary， the CD/AuNPs aptasensor developed in this study successfully overcomes the problems of high cost and insufficient detection limit in traditional detection methods. It offers advantages such as low cost， ease of operation， and a low detection limit， providing a promising new strategy for the early diagnosis of Alzheimer′s disease.
