Template Dissolution Interfacial Patterning of Single Colloids for Nanoelectrochemistry and Nanosensing

TL;DR

This paper introduces TDIP, a novel technique for assembling single colloidal gold nanoparticles onto various substrates with high yield, enabling advanced nanoelectrochemical and sensing applications without adhesive layers.

Contribution

The paper presents TDIP, a new method that allows high-yield, adhesion-layer-free assembly of colloidal nanoparticles onto diverse surfaces for nanodevice fabrication.

Findings

Achieved over 98% printing yield with TDIP.

Enabled direct electrical junctions for electrochemical applications.

Created nanoparticle-on-mirror structures for molecular sensing.

Abstract

Deterministic positioning and assembly of colloidal nanoparticles (NPs) onto substrates is a core requirement and a promising alternative to top down lithography to create functional nanostructures and nanodevices with intriguing optical, electrical, and catalytic features. Capillary-assisted particle assembly (CAPA) has emerged as an attractive technique to this end, as it allows controlled and selective assembly of a wide variety of NPs onto predefined topographical templates using capillary forces. One critical issue with CAPA, however, lies in its final printing step, where high printing yields are possible only with the use of an adhesive polymer film. To address this problem, we have developed a template dissolution interfacial patterning (TDIP) technique to assemble and print single colloidal AuNP arrays onto various dielectric and conductive substrates in the absence of any adhesion layer, with printing yields higher than 98%. The TDIP approach grants direct access to the interface between the AuNP and the target surface, enabling the use of colloidal AuNPs as building blocks for practical applications. The versatile applicability of TDIP is demonstrated by the creation of direct electrical junctions for electro- and photoelectrochemistry and nanoparticle-on-mirror geometries for single particle molecular sensing.