Fabrication of handmade paper sensor based on silver-cobalt doped copolymer-ionic liquid composite for monitoring of vitamin D3 level in real samples

Abstract This paper describes the synthesis of novel material and its application to fabricate a sensing tool for the diagnosis of vitamin D deficiency. A simple and economical route for the synthesis of novel composite material based on silver-cobalt (Co-Ag) doped polyaniline-polypyrrole (PANI-PPY) copolymer and ionic liquid (IL) has been described and used as sensing material for vitamin D3 detection. The synthesized composite was characterized using structural, morphological and electrochemical techniques. Co-Ag/PANI-PPY/IL was first used to modify the glassy carbon electrode (GCE) and applied for vitamin D3 detection. Later a conductive ink of the proposed material was prepared and a handmade paper sensor was fabricated. Co-Ag/PANI-PPY/IL@GCE and paper electrode showed excellent electrochemical behavior towards vitamin D3 oxidation within the concentration range of 0.0125–22.5 µM and 0.025–0.125 µM with the acceptable detection limit of 0.0073 µM and 0.015 µM respectively. Co-Ag/PANI-PPY/IL@GCE and paper electrode were successfully applied for the detection of vitamin D3 in serum and urine samples.