Room Temperature Detection of Acetone by a PANI/Cellulose/WO3 Electrochemical Sensor

Chemical sensing based on semiconducting metal oxides has been largely proposed for acetone sensing, although some major technical challenges such as high operating temperature still remain unsolved. This work presents the development of an electrochemical sensor based on nanostructured PANI/cellulose/WO3 composite for acetone detection at room temperature. The synthesized materials for sensor preparation were polyaniline (PANI) with a conductivity of 13.9 S/cm and tungsten trioxide (WO3) in monoclinic phase doped with cellulose as carbon source. The synthesized materials were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), cyclic voltammetry (CV), and Raman spectroscopy. The composite was applied for acetone detection in the range of 0 to 100 ppmv at room temperature with electrochemical impedance spectroscopy (EIS) for monitoring resistance changes proportional to acetone concentration. The developed sensor achieved a calculated limit of detection of 10 ppm and R2 of 0.99415 with a RSD of 5% (n=3) at room temperature. According to these results, the developed sensor is suitable for acetone sensing at room temperatures without the major shortcomings of larger systems required by high operating temperatures

Synthesis of nanoparticles of the chitosan-poly((α,β)-DL-aspartic acid) polyelectrolite complex as hydrophilic drug carrier

In this work, nanoparticles of the chitosan-poly((α,β)-DL-aspartic acid) polyelectrolyte complex (PEC) were synthesized. The purpose is to develop a biodegradable, biocompatible, and non-toxic polymeric platform as a vehicle for the encapsulation of hydrophilic drugs. The ionotropic gelation method, using solutions of chitosan and poly((α,β)-DL-aspartic acid sodium salt), allowed synthesizing particles with diameters of 142.1 ± 2.9 nm determined by DLS, while by FESEM particle diameters in the 60–200 nm range were observed. A preliminary trial showed that encapsulation of isoniazid, a hydrophilic drug to treat tuberculosis, is possible with encapsulation efficiency in the range of 5.3–5.8%