Self-activating zinc oxide encapsulated polyaniline-grafted chitosan composite for potentiometric urea sensor

The healthcare sector is always focused on the development of innovative functional nanomaterials, approaches, and devices for the detection of metabolites to cure and control the critical diseases. In this context, the present paper reports the synthesis of an axially oriented, biocompatible ternary hybrid composite of zinc oxide, polyaniline, and chitosan by in situ polymerization and composite formation technique. The prepared materials were characterized by Fourier transform-infrared spectrometer, X-ray diffraction, scanning electron microscope, and two-probe method. The analytical result designates the formation of ZnO-encapsulated polyaniline grafted chitosan (ZnO-en/PANI-g-CHIT) composite with improved electrical conductivity, chemically stability and self-activating in nature. Furthermore, a film of ZnO-en/PANI-g-CHIT hybrid matrix was casted onto an indium tin oxide coated glass slide by spin coating technique for potentiometric sensing of urea after immobilization of ureasee. Thus, obtained film was found suitable as an electrode with a sensitivity of 187.5 µV ppm⁻¹ cm⁻², response time of 3 min, recovery time of 30 s and limit of detection 29.84 ppm for self-activating potentiometric urea sensing in the range of 20 ppm to 500 ppm of natural as well as artificial samples. Fabricated bio-electrode was stable for eight weak with consistent sensitivity as well as highly specific for urea sensing in the presence of respective interferents in comparison to several reported urea sensors. Furthermore, it is proposed that the developed urea sensor could be a promising sensing strategy for advanced clinical applications because of comparable performance to commercial method.