Chiral plasmonic nanocrystals for generation of hot electrons: towards polarization-sensitive photochemistry

TL;DR

This paper demonstrates how chiral bio-assembled plasmonic nanocrystals can generate hot electrons for polarization-sensitive photochemistry, enabling new chiral photochemical applications and control at the nanoscale.

Contribution

It introduces a novel approach combining bio-assembly of plasmonic nanocrystals with hot electron generation for polarization-sensitive photochemistry.

Findings

Chiral plasmonic nanocrystals produce strong circular dichroism signals.

Hot electrons enable polarization-sensitive surface photochemistry.

Potential applications include chiral recognition and nanoscale chiral growth.

Abstract

The use of biomaterials - with techniques such as DNA-directed assembly or bio-directed synthesis - can surpass top-down fabrication techniques in creating plasmonic superstructures, in terms of spatial resolution, range of functionality and fabrication speed. Particularly, by enabling a very precise placement of nanoparticles in a bio-assembled complex or a controlled bio-directed shaping of single nanoparticles, plasmonic nanocrystals can show remarkably strong circular dichroism (CD) signals. Here we show that chiral bio-plasmonic assemblies and nanocrystals can enable polarization-sensitive photochemistry based on the generation of energetic (hot) electrons. It is now established that hot plasmonic electrons can induce surface photochemistry or even reshape plasmonic nanocrystals. Here we show that merging chiral plasmonic nanocrystal systems and the hot-election generation effect offers unique possibilities in photochemistry - such as polarization-sensitive photochemistry promoting nonchiral molecular reactions, chiral photo-induced growth of a colloid at the atomic level and chiral photochemical destruction of chiral nanocrystals. Regarding practical applications, our study suggests interesting opportunities in polarization-sensitive photochemistry, chiral recognition or separation, and in promoting chiral crystal growth at the nanoscale.