Femtoliter Batch Reactors for Nanofluidic Scattering Spectroscopy Analysis of Catalytic Reactions on Single Nanoparticles

TL;DR

This paper presents a novel femtoliter-scale nanofluidic batch reactor that allows for the study of catalytic reactions on single nanoparticles with controlled conditions and real-time spectroscopic readout.

Contribution

Introduction of a 4.8 femtoliters nanofluidic batch reactor with a gas-controlled opening mechanism for single nanoparticle catalysis analysis.

Findings

Successful demonstration of catalytic reduction on a single nanoparticle

Reactor volume of 4.8 femtoliters enables confinement and control

Nanofluidic scattering spectroscopy provides real-time reaction insights

Abstract

Macroscopic batch reactors are a core concept in chemical synthesis and catalysis due to their ability to ensure high conversion rates of the used reactants. At the nanoscale, such reactors hold promise due to their potential to enable chemistry in confinement under well-controlled mass transport conditions, and as enablers for the characterization of catalytic reactions on tiny active surface areas, such as single nanoparticles. However, their practical implementation and the readout of reaction products if used for the study of catalytic reactions is challenging due to their tiny volume and the requirement of being able to transiently open and close such nanoscopic batch reactors. Here, we introduce a liquid phase nanofluidic batch reactor concept with a volume of 4.8 femtoliters that conveniently can be opened and closed using a bypassing N2 gas stream, and that in combination with nanofluidic scattering spectroscopy readout enables the characterization of a catalytic reaction on a single nanoparticle inside the reactor, as we demonstrate on the catalytic reduction of fluorescein by sodium borohydride on a Au catalyst.