Polypyrrole and enzyme free cholesterol flakes based composite: Selective determination of theophylline.

In the present work, we demonstrated the non-enzymatic theophylline (TP) detection using nanostructured Polypyrrole (Ppy) and Cholesterol (Ch) flakes coordinated nanocomposite coated on Glassy Carbon Electrode. The higher active surface area and good mechanical stability of the Ppy integrated Ch composite exhibited better oxidation towards TP. The electron transfer across hydrogen bonding is of fundamental importance in enhancing the biochemical process in this biosensor system. Further, the scan rate analysis confirmed the quasi-reversible diffusion controlled electrochemical process. The differential pulse voltammetry report of the electrocatalyst shows a linear response of TP in the concentration range 1μM - 1 mM with detection limit of 720 nM (S/N = 3σ/b). The proposed electrochemical sensor exhibited intriguing sensing properties with good selectivity, reproducibility towards TP detection without any surface fouling. The overall analysis confirmed that the prepared nanocomposite modified electrode has quantified better accuracy towards target molecule without the aid of any bio receptors and binders in tea leaves and human urine samples.