On the Local Nanoscale Temperature Distributions in Photothermal Systems

Accurate temperature measurement at the nanoscale is essential for a wide range of applications in nanomedicine, energy conversion, and materials science. In this study, we present a theoretical framework to determine the minimum number of nanoparticles required to obtain statistically meaningful temperature readings based on thermal fluctuations and ensemble averaging. Using principles from statistical mechanics and thermodynamics, we derive criteria that link nanoparticle count, measurement variance, and thermal resolution. We further raise a fundamental but largely overlooked question: Can a well-defined temperature profile exist at the nanoscale, and if so, what are its spatial boundaries? This work provides a conceptual and statistical foundation for understanding nanoscale temperature distributions in photothermal systems, with thermodynamic implications for diagnostics, thermal therapy, and nanoscale energy applications.