Studies on clay-gelatin nanocomposite as urea sensor

Abstract

Homogeneous gelatin organogel-based nanocomposite (GA-NC) was prepared by Lap as fillers. For customized thermal and viscoelastic properties, saturation binding of Lap to GA chain was probed in aqueous solution, and Lap=0.03% (w/v), (glycerol)=30% (v/v) and (GA)=3% (w/v) was used for organogel nanocomposite. The Lap platelets were successfully exfoliated in the organogel matrix giving rise to a homogeneous phase. The interaction of GA-NC with urea was studied using electrochemical as well as optical technique. For electrochemical study, a thin film of this GA-NC was prepared onto indium tin oxide (ITO) coated glass plate via drop-casting. This GA-NC/ITO electrode was characterized by electrochemical, FTIR and SEM techniques. This GA-NC/ITO electrode exhibited electrochemical response specific for urea with sensitivity of 32.7 and 5.56µA mM−2 cm−2 in the two concentration range of 0.1 to 2 and 2 to 20mM, respectively. The electrochemical profile of this electrode was sensitive towards urea which opens up the possibility for development of strip-based enzyme-free sensors for field applications. This GA-NC material in solution phase also shows optical response for urea with binding constant of 63.93M−1.