A low-cost flexible material system made of PANI/graphite for resistive detection and quantitative determination of urea

The designing of low-cost, flexible, and easily degradable sensors with organic materials compositions is a challenging one in recent advancements in sensor technology. In order to develop a high-performance sensing device for urea, polyaniline (PANI) deposited on the surface of graphite (Gr) incorporated cellulose paper substrate has been studied. A graphite layer was formed by using commercially available pencil graphite by gently rubbing on one side of the cellulose paper substrate. A uniform layer of PANI was obtained over the graphite-incorporated cellulose paper by a simple physical vapor deposition technique. The prepared sensor material systems of polyaniline/graphite (PANI/Gr) have been studied by using scanning electron microscopy (SEM), X-ray diffraction analysis, ultraviolet–visible spectroscopy, and Keithley 2450 source meter unit for composition, morphology, optical and charge transport properties respectively. The resistive response of these materials with different molar concentrations of urea was studied through I–V characteristics and a notable urea sensing property has been observed. The PANI/Gr composite prepared on a cellulose substrate evolved as an active sensing material for low-cost, non-enzymatic detection of urea.