Confinement Effect of Plasmon for the Fabrication of Interconnected AuNPs through the Reduction of Diazonium Salts.

Luong-Lam Nguyen,Jean-Christophe Lacroix,Mathieu Bastide,Quang-Hai Le,Sarra Gam-Derouich,Van-Nhat Pham,Van-Quynh Nguyen

doi:10.3390/nano11081957

Abstract

This paper describes a rapid bottom-up approach to selectively functionalize gold nanoparticles (AuNPs) on an indium tin oxide (ITO) substrate using the plasmon confinement effect. The plasmonic substrates based on a AuNP-free surfactant were fabricated by electrochemical deposition. Using this bottom-up technique, many sub-30 nm spatial gaps between the deposited AuNPs were randomly generated on the ITO substrate, which is difficult to obtain with a top-down approach (i.e., E-beam lithography) due to its fabrication limits. The 4-Aminodiphenyl (ADP) molecules were grafted directly onto the AuNPs through a plasmon-induced reduction of the 4-Aminodiphenyl diazonium salts (ADPD). The ADP organic layer preferentially grew in the narrow gaps between the many adjacent AuNPs to create interconnected AuNPs. This novel strategy opens up an efficient technique for the localized surface modification at the nanoscale over a macroscopic area, which is anticipated to be an advanced nanofabrication technique.

Highlights

Advances in miniaturization technologies have attracted enormous interest due to their effectiveness in the fabrication of smaller, faster, and cost-effective devices
This paper demonstrates experimentally the plasmon-induced reduction of 4Aminodiphenyl diazonium salts and the deposition of oligo (4amino-diphenyl) (ADP) at the hotspot region of approach to selectively functionalize gold nanoparticles (AuNPs) deposited on the indium tin oxide (ITO) surface (Figure 1)
To generate plasmonic substrates for studying the reduction of diazonium salts triggered by plasmon, spherical AuNPs were electrochemically deposited on transparent ITO

Summary

Introduction

Advances in miniaturization technologies have attracted enormous interest due to their effectiveness in the fabrication of smaller, faster, and cost-effective devices. Various nanosized multifunctional surfaces have been manufactured for sensing systems [1,2,3,4], switching electronic devices [5,6], light-emitting systems [7] and energy storage devices [8]. Nanostructured surfaces are fabricated by using either top-down or bottom-up approaches. The fabrication processes based on top-down methods remain time-consuming, expensive, require complicated facilities and show limited resolution [12]. They cannot be the only response to the growing demands for product miniaturization

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Conclusion