Fig. 1. Analysis framework for nanoparticle heating-induced protein denaturation and characteristics of protein denaturation under nanoscale-confined heating (NCH) and macroscale-collective heating (MCH). (A) Schematic of the analysis framework for nanoparticle (NP) array heating and the resulting protein denaturation (D) or activation. External excitation of the NP array (each NP as a nano heater) heats up the NP and the surrounding media. The temperature increase drives a chemical reaction (protein denaturation or activation), which can be described by first-order kinetic model (the Arrhenius model). Integration of the reaction rate over time leads to an overall protein denaturation or activation. (B and C) Nanoscale confined heating (NCH) and macroscale collective heating (MCH), and the corresponding temperature increase and protein denaturation. Conditions: domain size 10 μm × 10 μm, NP diameter (d_NP) = 30 nm, heating power per NP (g) is (B) 35.6 μW and (C) 18 nW, NP area density is (B) 9 μm⁻² and (C) 100 μm⁻², and excitation duration is (B) 10 ns and (C) 1 μs.