Vu Chris, Yan Junhong, de Jong Arthur M, Prins Menno W J
Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, 5612 AZ, The Netherlands.
Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, 5612 AZ, The Netherlands.
Adv Sci (Weinh). 2025 Feb;12(7):e2412181. doi: 10.1002/advs.202412181. Epub 2024 Dec 24.
Biomolecular sensors with single-molecule resolution are composed of multitudes of transducers that measure state changes related to single-molecular binding and unbinding events. Conventionally, signals are aggregated from many individual transducers in order to achieve sufficient statistics. However, by aggregating signals, transducer-to-transducer differences are lost and heterogeneities cannot be studied. Here, transducers with single-molecule resolution over long time spans are studied, enabling the collection of sufficient statistics from independent transducers. This allows comparisons between transducers that reveal fundamental heterogeneities in their molecular assemblies related to stochastic variations. The study is performed with biosensing by particle motion, a sensing methodology with thousands of particles that dynamically interact with a sensing surface. The signals of individual particles are studied for series of modulations of analyte concentration over 25 h. The results show large differences in individual concentration-dependent responses. Monte Carlo simulations clarify that heterogeneities can be attributed to stochastic fluctuations in the numbers of binder molecules, and that gradual changes of the response characteristics can be related to losses of molecules in the single-particle transducers. The results give insights into molecular and temporal heterogeneities of continuous transducers with single-molecule resolution and explain how sensors can be engineered to achieve robust, precise, and stable biomolecular monitoring.
具有单分子分辨率的生物分子传感器由众多换能器组成，这些换能器可测量与单分子结合和解离事件相关的状态变化。传统上，为了获得足够的统计数据，信号是从许多单个换能器聚合而来的。然而，通过聚合信号，换能器之间的差异就会丢失，异质性也无法得到研究。在此，对长时间跨度内具有单分子分辨率的换能器进行了研究，从而能够从独立的换能器收集足够的统计数据。这使得能够对换能器进行比较，揭示其分子组装中与随机变化相关的基本异质性。该研究采用粒子运动生物传感进行，这是一种具有数千个与传感表面动态相互作用的粒子的传感方法。对单个粒子的信号进行了长达25小时的一系列分析物浓度调制研究。结果显示了个体浓度依赖性响应的巨大差异。蒙特卡罗模拟表明，异质性可归因于结合分子数量的随机波动，响应特性的逐渐变化可能与单粒子换能器中分子的损失有关。这些结果深入了解了具有单分子分辨率的连续换能器的分子和时间异质性，并解释了如何设计传感器以实现稳健、精确和稳定的生物分子监测。
