改良型ISFET的感測器架構並用於檢測Troponin I

Abstract

隨著醫療的進步，我們的重點不僅應該放在治療疾病上，還應該關注預防疾病。在疾病預防中，測量生物標記物的濃度對於評估疾病進展十分重要。與此同時，隨著半導體技術的快速發展，「離子敏感型場效應電晶體」（ISFET）經常被用作檢測與各種疾病相關的生物分子傳感器。然而，這個半導體元件受限於能斯特物理極限，在室溫（298.15K）下其最大靈敏度約為 59.16 mV/pH，這樣的特性限制了其感測能力。

因此，本研究希望設計具有增強感測響應的 ISFET 晶片，以 ISFET 為核心元件，提出可以提升性能突破感測靈敏度的感測元件架構。首先，我們從元件架構入手，設計了一種新型雙閘極 ISFET 結構，並使用後製程技術測量了兩種類型的感測膜，即 TiN 和 Al2O3。此外，也藉由量測架構著手，將分壓電路與感測器元件集成，進一步使相關感測元件具有調整放大因子的能力。最後，我們也探索了感測區域形狀與面積的不同設計，以研究其對感測穩定性能的影響。

在本論文中，我們通過各種晶片架構放大了感測響應，實現了超越原始能斯特極限的表現；此外，我們比較了不同形狀和面積的感測區域的穩定性，確認了較長的周長和更多的幾何角會導致感測性能下降；最後，我們將這樣的新設計應用在Troponin I 的感測，並且成功放大 Troponin I 感測的表現。這一系列研究為未來的感測器晶片應用提供了寶貴的養分。

With advancements in medical technology, the focus should not only be on disease treatment but also on disease prevention. In disease prevention, measuring the concentration of biomarkers is crucial for assessing disease progression. Meanwhile, with the rapid development of semiconductor technology, ion-sensitive field-effect transistors (ISFETs) have been widely used as biosensors for detecting disease-related biomolecules. However, this semiconductor device is constrained by the Nernstian physical limit, where its maximum sensitivity is approximately 59.16 mV/pH at room temperature (298.15 K), thereby limiting its sensing capabilities.

Therefore, this study aims to design an ISFET-based sensor with enhanced sensing response by proposing a sensor architecture that can improve performance and surpass the sensing sensitivity limit. First, we designed a novel dual-gate ISFET structure from a device architecture perspective and employed post-processing techniques to evaluate two types of sensing membranes, namely TiN and Al₂O₃. Additionally, we integrated a voltage divider circuit with the sensing device to enable tunable gain adjustment, further enhancing the sensing capability. Furthermore, we explored different designs of sensing area shapes and dimensions to investigate their impact on sensing stability.

In this study, we successfully enhanced the sensing response beyond the intrinsic Nernst limit through various device architectures. Moreover, by comparing sensing areas with different geometries and sizes, we confirmed that a longer perimeter and a greater number of geometric corners lead to a decline in sensing stability. Finally, we applied this novel sensor design to the detection of Troponin I and successfully amplified the Troponin I sensing signal. This series of investigations provides valuable insights for the future development of semiconductor-based biosensor chips.