报告题目：Single-Molecule Mechanochemical Sensing
报 告 人：Prof. Hanbin Mao(茅涵斌)
Kent State University, USA
邀 请 人 ：张文科教授
茅涵斌教授，1995年毕业于华西医科大学药学院药物化学专业。随后分别在美国波士顿大学和德克萨斯A&M大学获得硕士和博士学位。2003年至2005年在加州大学伯克利分校从事博士后研究，现为美国肯特州立大学教授。茅涵斌教授主要研究方向包括：1.利用单分子激光光镊和磁镊技术进行的生物大分子研究，主要内容包括生物大分子构象研究、生物分子间相互作用机理的研究；2 .利用单分子技术构建超灵敏生物传感器等。迄今在Nature Chem., Nature Nano., PNAS，JACS, Angewandte Chemie, Nucleic Acids Research等顶尖学术期刊上发表文章数十篇。
Single-Molecule Mechanochemical Sensing
Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242
Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242
Traditional biosensors constitute two elements, molecular recognition and signal amplification. The first element determines specificity of the sensing while the second component decides sensitivity of the sensing. In a typical setup, these two components are spatiotemporally decoupled. In the widely used ELISA strategy, for example, chemical amplifications are usually performed once the molecular recognition is complete. As amplification requires additional time to accomplish, it is challenging for this method to detect analyte in real time, which is highly desirable when the ligand of interest has transient lifetimes. Another problem for decoupled sensing components lies in the fact that extra steps are required to prevent the cross-talks between the two components. These additional steps bring new errors for the sensing, deteriorating the signal-to-noise level.
In this presentation, I will discuss a new sensing strategy that exploits mechanochemical coupling inside biomacromolecular templates, DNA in particular. Mechanochemical coupling reflects the interaction between covalent/non-covalent chemical bonds in a molecule and mechanical stress experienced by the molecule. It is a key subject in the newly emerged field, mechanochemistry, which has led to a number of exotic applications in materials chemistry. However, mechanochemical principles have not been well explored in chemical sensing. Using force-based single-molecule techniques, such as optical tweezers, our group has been able to follow change in the tension of individual DNA templates upon recognition of targets. The mechanochemical coupling occurs instantaneously, enabling real time detection of analytes. Since the template we use is single-molecular in nature, the ultimate single-molecule sensitivity can be achieved. Combined with a microfluidic platform, this sensing strategy has allowed us to detect picomolar concentrations of specific targets in biological samples.