Understanding the fundamental workings of biological systems requires a deep exploration of nonequilibrium processes, which are at the heart of life’s dynamic and energy-driven nature. Biological activities such as cell division, transport, and molecular movement rely on a network of molecular motors that transform chemical energy from fuel molecules, like ATP, into mechanical work while dissipating heat. This process of energy dissipation, also known as entropy production, is essential for sustaining cellular functions and maintaining homeostasis. However, accurately measuring the dissipation of free energy in such complex systems remains a challenge due to limited experimental access to all interacting components and degrees of freedom.
The overarching objective of this project is to bridge the gap between theoretical tools in stochastic thermodynamics and their application in real-world biological experiments. Existing theoretical frameworks provide mathematical methods for quantifying nonequilibrium behavior, but their practical utility is often constrained by incomplete experimental data, which can obscure true measurements of energy loss and cause the system’s activity to appear as passive thermal fluctuations.
To tackle this challenge, the project aims to develop and implement innovative experimental tools—specifically, fluorescent nanosensors based on single-walled carbon nanotubes (SWCNTs). These nanosensors, tailored with precise functionalizations, are designed to detect and transduce the activity of molecular motors into measurable changes in fluorescence. This novel approach introduces a new dimension of observation by allowing the emitted fluorescence of SWCNTs to act as a phase-space coordinate for tracking energy dissipation in living and synthetic systems.
The project focuses on integrating these sensors into controlled biomimetic systems, such as DNA-gel matrices and reconstituted cytoskeletons, to map and understand energy dissipation in simplified but active environments. Subsequently, the research extends to internalizing these nanosensors in live cells to estimate entropy production at the cellular level, offering insights into intracellular organization and energy dynamics.
In parallel with experimental work, the project develops theoretical tools that use advanced data analysis techniques, including algorithms for assessing time-irreversibility and entropy production from partial data. By refining these tools, we aim to provide more reliable and practical methods for evaluating dissipation, even when only partial or coarse-grained experimental data is available.
The expected impact of this research is the enhancement of our understanding of the thermodynamics underlying biological systems and the development of non-invasive methods for measuring cellular and molecular activity.
