A Comparative Study of Polypyrrole and Ag/Polypyrrole Hybrid Nanocomposites as Sensitive Material Used for New Dry Polarizable Bioimpedance Sensors

Gabriela Telipan,Virgil Marinescu,Ioana Ion,Eduard-Marius Lungulescu,Lucian Pîslaru-Dănescu

doi:10.3390/app11094168

Abstract

Three types of dry polarizable electric bioimpedance sensor for skin bioimpedance monitoring without skin preparation have been developed. The sensitive materials as a component of these sensors are the conductive polypyrrole and hybrid nanocomposite polypyrrole-Ag, with 10% and 20% Ag incorporated in the polypyrrole matrix. The hybrid nanocomposites Ag nanoparticles (NPs)/polypyrrole were obtained by introducing the colloid solution of Ag NPs in pyrrole solution, followed by polymerisation, and calculated for 10% and 20% of monomer’s mass. The structural characterisation and morphological analysis of these sensitive materials were carried-out by Raman spectrometry, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. In making the electrodes, the technique of pressing powders of polypyrrole and hybrid composites Ag NPs/polypyrrole in a hydraulic press was used in the form of a disk. The electric bioimpedance performance of sensors was investigated using a two-point method in the frequency range of 1–300 kHz, at a voltage of 2 Vpeak-peak, on six human subjects, three men and three women. For these three bioimpedance sensors, it was found that the electric bioimpedance of the skin decreases across the frequency range and shows good linearity of the impedance-frequency curve on the range frequency of interest in bioimpedance measurements.

Highlights

IntroductionElectrical impedance of biological tissue, named electric bioimpedance, is used for medical diagnosis due to properties such as the possibility of monitoring organs and tissues’
This paper presents a new dry polarizable bioimpedance sensor based on polypyrrole and silver (Ag) nanoparticles (NPs)/polypyrrole hybrid nanocomposites
The Raman spectrum shows an increase of the band intensity, positioned at around 1605 cm−1, with the amount of silver, which concludes that the increase of the percentage of silver causes modifications of the crystalline structure of the polypyrrole

Summary

Introduction

Electrical impedance of biological tissue, named electric bioimpedance, is used for medical diagnosis due to properties such as the possibility of monitoring organs and tissues’. State, both in vivo and in vitro modes. It can offer the relatively simple possibility of technological achievement for bioimpedance sensors [1]. Bioimpedance presents an advantage because it is a technique that provides health information in a non-invasive way. This medical technique involves an injection of alternating electric current in human tissues at very low intensity. In the technique of bioimpedance measurements, performed under the influence of the injected electric current, the biologic tissues, organs, cells medium behave like conductors, dielectrics, or insulators, each depending on their composition

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Conclusion