Electrical detection of plasmon-induced isomerization in molecule-nanoparticle network devices

TL;DR

This study demonstrates that plasmon-induced isomerization in molecule-nanoparticle networks can be electrically detected, showing faster kinetics than optical methods, with potential mechanisms including electric fields and resonant energy transfer.

Contribution

It provides the first electrical detection of plasmon-induced isomerization in nanoparticle networks, highlighting the efficiency of 3D structures and proposing likely underlying mechanisms.

Findings

PII is more efficient in 3D-like networks than in monolayers.

PII exhibits about 10 times faster kinetics than optical isomerization.

Resonant energy transfer is the most probable mechanism for PII.

Abstract

We use a network of molecularly linked gold nanoparticles (NPSAN: nanoparticles self-assembled network) to demonstrate the electrical detection (conductance variation) of a plasmon-induced isomerization (PII) of azobenzene derivatives (azobenzene bithiophene : AzBT). We show that PII is more efficient in a 3D-like (cluster-NPSAN) than in a purely two-dimensional NPSAN (i.e., a monolayer of AzBT functionalized Au NPs). By comparison with usual optical (UV-visible light) isomerization of AzBT, the PII shows a faster (a factor about 10) isomerization kinetics. Possible PII mechanisms are discussed: electric field-induced isomerization, two-phonon process, plasmon-induced resonant energy transfer (PIRET), the latter being the most likely.