Development of electrochemical immunosensors based on different serum antibody immobilization methods for detection of Japanese encephalitis virus

Quang Huy Tran, Thi Hong Hanh Nguyen, Anh Tuan Mai, Thi Thuy Nguyen, Quang Khue Vu and Thi Nga Phan

Abstract

This paper describes the development of electrochemical immunosensors based on human serum antibodies with different immobilization methods for detection of Japanese encephalitis virus (JEV). Human serum containing anti-JEV antibodies was used to immobilize onto the surface of silanized interdigitated electrodes by four methods: direct adsorption (APTES-serum), covalent binding with a cross linker of glutaraldehyde (APTES-GA-serum), covalent binding with a cross linker of glutaraldehyde combined with anti-human IgG (APTES-GA-anti-HIgG-serum) and covalent binding with a cross linker of glutaraldehyde combined with a bioaffinity of protein A (APTES-GA-PrA-serum). Atomic force microscopy was used to verify surface characteristics of the interdigitated electrodes before and after treatment with serum antibodies. The output signal of the immunosensors was measured by the change of conductivity resulting from the specific binding of JEV antigens and serum antibodies immobilized on the electrodes, with the help of horseradish peroxidase (HRP)-labeled secondary antibody against JEV. The results showed that the APTES-GA-PrA-serum method provided the highest signal of the electrochemical immunosensor for detection of JEV antigens, with the linear range from 25 ng ml⁻¹ to 1 μg ml⁻¹, and the limit of detection was about 10 ng ml⁻¹. This study shows a potential development of novel electrochemical immunosensors applied for virus detection in clinical samples in case of possible outbreaks