The Effect of Gold Nanoparticle on Electrical Impedance of Tissue on Low Frequency Ranges

Introduction: Electrical impedance of tissues on low frequencies includes useful information about functional and structural changes in tissues. This property is used in Electrical Impedance Tomography (EIT) imaging modality for the detection of lesions in tissues.Objective: The goal of this article is to study changes in electrical impedance of tissues in the presence of gold nanoparticles.Materials and Methods: Spherical gold nanoparticles with size of ۲۰-۲۵ nm were synthesized with Turkevich method. Size distribution and shape of nanoparticles were characterized by transmission electron microscopy (TEM). Electrical impedance of two types of phantoms (chicken fat and muscle paste tissues) was measured by ۴-electrode method with and without gold nanoparticles.Results: Results demonstrate a reduction in electrical impedance of tissues in the presence of gold nanoparticles. However, this reduction is not the same for fat and muscle tissues. Reductions in resistive impedance are  for fat and muscle tissues on the frequency of ۱ KHz, respectively. A reduction in electrical impedance is accompanied by a rise in electrical conductance leading to increase in EIT signal.Conclusion: As signal enhancement is different for fat and muscle tissues; presence of gold nanoparticles could be used to improve EIT image contrast.

Keywords:

Contrast Agent , Electrical Impedance , Gold Nanoparticle , Medical Imaging