Application of egg yolk IgY on carboxylated polypyrrole films for impedimetric detection of PfHRP2 antigen

Abstract

This paper described an impedimetric immunosensor for detecting Plasmodium falciparum histidine-rich protein 2 (PfHRP2). Antibodies from egg yolk (Ab-PfHRP2, IgY type) were linked covalently to the screen-printed gold electrodes (SPGE) surface modified with a thin film of Poly-pyrrole-pyrrole 3 carboxylic acid (P(Py-Py3COOH) to develop the sensing platform. The fabrication steps were followed by microscopic (scanning electron microscopy), spectroscopic (RAMAN spectroscopy and Energy-dispersive X-ray spectroscopy), and electrochemical (electrochemical impedance spectroscopy (EIS) and cyclic voltammetry) techniques. The determination of Ag-PfHRP2 was performed by EIS, and the BSA(bovine serum albumin)/Ab-PfHRP2(IgY)/P(Py-Py3COOH)/SPGE immunosensor recorded a linear response at 100-1000 ng mL^-1 concentration range, with a limit of detection (LOD) of 27.47 ng mL^-1. Its performance was confirmed by Enzyme-Linked Immuno-Sorbent Assay. The fabricated device uses a simple strategy of IgY immobilization, showing high sensitivity and good selectivity, and can be considered an alternative for carrying out malaria tests.

Keywords: Histidine-rich protein 2; IgY antibodies; Impedimetric immunosensor; Malaria; Polypyrrole films; Screen-printed gold electrodes.