Label-free electrochemical albumin immunosensor based on gold nanoparticle modified polyaniline nanofiber electrode

Abstract

SUMMARY Clinical studies have shown that urine albumin is highly related to chronic kidney disease (CKD) CKD can be divided into five stages and if abnormal kidney function can be identified and treated at early stage the patients can recover their healthy state Conversely the patients with CKD at middle and late stages won’t recover their healthy state and require the use of drugs or dialysis to slow down the deterioration of the disease To prevent the kidney failure it is therefore indispensable to develop a sensor with high accuracy towards the detection of urine albumin In this study gold nanoparticles modified polyaniline nanofiber electrode was prepared and used as the substrate for the immobilization of albumin antibody When the albumin antibody interacts with albumin to form the albumin antibody-antigen complex the diffusion path of [Fe(CN)6]3-/[Fe(CN)6]4- redox couples from the bulk electrolyte to the electrode surface will be blocked which results in the increase in the interfacial charge transfer resistance The changes in the resistance induced by the albumin can therefore be used as the basis for the detection of urine albumin The optimization on the conditions for the electrodeposition of gold nanoparticles was performed with an aim at achieving the uniform modification of the gold nanoparticles on the surface of the polyaniline nanofibers increasing the surface area available for antibody immobilization and increasing the sensitivity of the sensor The physical and chemical properties of the modified electrode were analyzed by scanning electron microscope transmission electron microscope and Raman spectroscopy and the sensing performance of the electrode was analyzed by AC electrochemical impedance spectroscopy The results show that the developed albumin electrochemical immune sensor has excellent sensing performance including high sensitivity (24 52 log(mg/dL)) low detection limit (0 02 mg/dL) and wide linear range (0 02- 30 0?mg/dL) and high accuracy (error

Date of Award	2020
Original language	English
Supervisor	Chia-Yu Lin (Supervisor)