Related Experiment Video
Updated: Feb 15, 2026

A Closed-Type Wireless Nanopore Electrode for Analyzing Single Nanoparticles
Published on: March 20, 2019
Structural Change of a Single Ag Nanoparticle Observed by Dark-field Microspectroscopy
Jie Pang1, Hai-Ling Liu1, Jian Li1
1State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210023, China.
Abstract:
Silver nanoparticles (AgNPs) have been widely used as photocatalysts and nanosensors. Observation of the spectroscopy of a single AgNP greatly helps us understand the catalytic characteristics and morphology change of the AgNP during reactions. In the present study, AgNPs physically adsorbed on indium tin oxide (ITO) conductive glass were electrochemically reduced and oxidized, and the plasmonic resonance Rayleigh scattering (PRRS) spectrum of an individual AgNP was observed under a dark-field microscopy (DFM) equipped with a spectrometer. The electrochemical oxidization of the AgNP under constant potential caused a redshift of the PRRS peak for 30±5 nm. However, electrochemical reduction of the AgNP could not make the PRRS peak completely shift back to the initial position. In situ AFM and SEM characterization confirmed that very small Ag fragments (<10 nm) formed around the AgNP core during electrochemical oxidization. Results showed that dark-field microspectroscopy could be used as a sensitive tool for estimating the morphology/structural changes of nanoparticles that can hardly be observed through the cyclic voltammograms of multiple AgNPs.
Related Concept Videos
Dark Triad and Person Perception
Naturalistic Observations
Global Climate Change
Rates of Change
Work Done During Volume Change
Consider a gas confined to a cylinder fitted with a movable piston at one end. If the gas expands from volume V1 to volume V2, it exerts a force on the piston, such that the piston moves by a distance dr.
The work done by the gas on the piston can be expressed as
Net Change Theorem

