Zeng Guan-Cheng, Huang Hsuan-Wei, Lin Chia-Kai, Chen Jung-Chih, Dong Guo-Chun, Hung Sheng-Chun, Wang Yu-Lin
Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, Taiwan.
Institute of Biomedical Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan.
Talanta. 2025 Feb 1;283:127138. doi: 10.1016/j.talanta.2024.127138. Epub 2024 Oct 31.
In this study, we developed a temperature-resistant aptamer coupled with extended gate electric double-layer Field-Effect Transistors (FETs) for highly sensitive mercury ion detection. The design of the temperature-resistant aptamer is based on the thermal and structural properties of the hairpin structure. Two aptamer sequences were designed with different melting temperatures (T) and compared for their sensitivity. The hairpin structure of the aptamer with a high melting temperature ensures the stable structure prior to the addition of the mercury ions, which allows the formation of thymine-mercury-thymine (T -Hg-T) complex in low concentrations of mercury ions. High sensitivity and low detection limit are achieved at elevated temperatures with the aptamer having a high melting temperature. The elevated temperature facilitates the reaction rate, resulting in high sensitivity and a low detection limit. The aptamer with a high melting temperature hairpin structure has shown a remarkable improvement in the limit of detection with a 4 orders of magnitude increase compared to the one with a low melting temperature. The sensor with the high melting temperature aptamer shows an extremely low detection limit of 4.68 × 10 M, surpassing previously reported results. The aptamer with a low melting temperature requires mercury ions to stabilize the hairpin structure by forming a T-Hg-T complex. The results show that if the melting temperature is lower than the ambient temperature, it is very difficult to detect low concentrations of mercury ions at the ambient temperature. The selectivity of this sequence was also tested against multiple heavy metals, including arsenic (As), lead (Pb), chromium (Cr), and cadmium (Cd) ions. This study has shown how the structural and thermal properties of the aptamer, and the ambient temperature affect the sensitivity. They are strongly correlated to the performance of the sensors and need to be considered in the design of the sequence.
在本研究中，我们开发了一种与扩展栅极电双层场效应晶体管（FET）相结合的耐温适配体，用于高灵敏度汞离子检测。耐温适配体的设计基于发夹结构的热学和结构特性。设计了两个具有不同解链温度（T）的适配体序列，并比较了它们的灵敏度。具有高解链温度的适配体的发夹结构可确保在添加汞离子之前结构稳定，这使得在低浓度汞离子中能够形成胸腺嘧啶 - 汞 - 胸腺嘧啶（T -Hg-T）复合物。具有高解链温度的适配体在升高的温度下实现了高灵敏度和低检测限。升高的温度促进了反应速率，从而实现了高灵敏度和低检测限。与具有低解链温度的适配体相比，具有高解链温度发夹结构的适配体在检测限方面有显著提高，检测限提高了4个数量级。具有高解链温度适配体的传感器显示出极低的检测限，为4.68×10⁻¹¹ M，超过了先前报道的结果。具有低解链温度的适配体需要汞离子通过形成T -Hg-T复合物来稳定发夹结构。结果表明，如果解链温度低于环境温度，在环境温度下很难检测到低浓度的汞离子。还针对多种重金属，包括砷（As）、铅（Pb）、铬（Cr）和镉（Cd）离子测试了该序列的选择性。本研究展示了适配体的结构和热学特性以及环境温度如何影响灵敏度。它们与传感器的性能密切相关，在序列设计中需要予以考虑。
