Inhomogeneous Strain-Modulated Phonon Scattering Sustains Hot Electrons for Enhanced Enzymatic Therapy.

Enzymatic therapy holds potential as a tumor therapeutic approach, yet enhancing the catalytic activity of nanozymes remains a challenge in tumor cells. Here, we designed a strain-engineered nanozymes (PWO) based on platinum (Pt) nanodots epitaxially grown on tungsten oxide (WOx) nanoribbons, which introduced inhomogeneous lattice strain. The phonon spectrums reveal the different influences on acoustic and optical branches caused by inhomogeneous strain. Enhanced acoustic phonon scattering promotes elastic electron-phonon interactions, enabling hot electrons to retain energy as confined lattice heat rather than dissipating as bulk photothermal output. Consequently, the photothermal conversion efficiency of WOx decreased from 37.19% (unstrained) to 20.80% (strained), confirming the formation of confined lattice heat. Under the synergistic effect of confined lattice heat and contact potential difference, the activation energy of the enzymatic catalytic reaction was reduced by 51.30% due to hot electrons. Moreover, PWO caused damage to mitochondria and the cytoskeleton, leading to the eventual induction of apoptosis in tumor cells. These results elucidate the physical manifestation of electron-phonon and phonon-phonon scattering under inhomogeneous strain and provide a general strategy for improving nanozyme catalysis via hot-electron regulation in enzymatic therapy.