Determinants of progressive reshaping-activity increase

Determine what causes the progressive increase in reshaping activity observed in some gold nanorods, including whether differences in initial interparticle connectivity or local environment account for its occurrence.

Background

The isolated nanorod NR 6 exhibits a sharp increase in the rate of reversible tip-to-tip switching during the first approximately 20 seconds of pulsed illumination, followed by saturation. The paper interprets this behavior as evidence for a cumulative structural ratchet, potentially involving changes in defect populations, surface facets, or a carbon shell that progressively lowers the barrier to reshaping.

However, the increase in activity is not observed universally. Some other active particles show a comparable rise, whereas others do not, and the paper identifies initial connectivity and local environment as plausible factors without determining their roles. Resolving this issue would clarify why individual nanorods respond differently to otherwise similar pulsed excitation.

References

This increase is, however, not universal: among other active particles, some show a comparable rise while others do not (Fig. S9). NR 6 shows it most clearly, and what determines whether it occurs, e.g. differences in initial connectivity or local environment are plausible factors, remains unresolved.

— Pulse-by-pulse imaging of reversible, collective reshaping in laser-excited gold nanorods  (2610.13383 - Dieperink et al., 9 Oct 2026) in Section “Pulse-resolved reshaping of an isolated nanorod”