Detection of single nanoparticle collisions by electrocatalytic amplification


Current detector/sensor technology has been used to detect the presence of molecules in substances quickly and with relatively high sensitivity. Conventional technology allows for this quick analysis when the substance being testing for is present in relatively high amounts. Analyzing particle size distributions of nanoparticles typically requires costly instrumentation and a trained operator. Techniques such as scanning or transmission electron microscopy couple with light scattering are the usual methods for such studies. However, none of these techniques provide any chemical information without the addition of a separate analytical system and software.

Researchers at The University of Texas have developed a new technique that can be used to determine size distribution of nanoparticles and, in many cases, provide information on the chemical identity of these particles. Additionally, this new electrochemical technique can detect binding between biomolecules at the single-molecule level with a much less expensive setup than the traditional fluorescence microscopy, surface plasmon resonance, or enhanced Raman and vibrational spectroscopy currently used for this purpose.

IP Status: US Patent Grant 9,096,430

Figure 1. Demonstration of analytical mechanism for detecting collisions of single nanoparticles and a typical result when a single catalytic nanoparticle collision is detected. An ultramicroelectrode is used in conjunction with a novel amplification scheme and catalytic reactions to produce a large current which can be correlated to the particle size, particle residence time, and the nature of the particle interaction with the electrode surface.