Fabricating Well-Ordered Nanoparticle Arrays via Scanning Electrochemical Cell Microscopy Opens a New Door for Electrochemical Sensing

Description:
Well-ordered arrays of nanostructured materials like Gold and Silver nanoparticles (NPs) on surfaces are good candidates for applications in electrochemical sensing, catalysis, energy conversion, etc. In these applications, well-ordered NPs would be ideal for improving reproducibility, repeatability, and stability in sensing applications or optimizing the mass transfer of species to valuable active materials in catalysis. As a potential biosensor, nanoparticles can enhance or supersede current analytical techniques, and their introduction could positively impact the research and medical community. It is incredibly challenging to produce well-defined nanostructured arrays using conventional fabrication methods, such as electrodeposition, due to the random, non-uniform chemical properties of heterogeneous interfaces and the stochastic nature of nucleation and growth processes. Here, we demonstrate scanning electrochemical cell microscopy (SECCM) can be utilized to modify electrode surfaces locally in a well-controlled fashion without any templates or surfactants through a simple one-step electrodeposition method. In this approach, an electrolyte-filled quartz capillary is used to form a miniaturized (<1 μm) electrochemical cell at the electrode surface, enabling the electrodeposition of individual nanoparticles of controlled size at precisely-defined locations. The efficacy of this SECCM-based approach was demonstrated by the fabrication, characterization, and functionalization of ordered gold nanoparticle arrays, revealing the potential for SECCM to serve as a powerful, flexible platform for the nanofabrication of platforms for biosensing applications.

Speaker: Md Maksudur Rahman - Ph.D. Candidate, Chemistry Department at the University of Wyoming