A Novel Electrochemical Immunosensor Based on Mesoporous Graphitic Carbon Nitride for Detection of Subgroup J of Avian Leukosis Viruses

The rapid and sensitive detecting technique for subgroup J of avian leukosis viruses (ALVs-J) needs to be developed as soon as possible in order to not only reduce economic losses but also ensure the food safety. In this paper, a novel electrochemical immunosensor was built based on mesoporous graphitic carbon nitride (mpg-C 3 N 4 ). Mpg-C 3 N 4 was used as the sensor platform to bond with the primary antibodies (Ab 1 ). The compound of thionine and mpg-C 3 N 4 (Th-mpg-C 3 N 4 ) was synthesized for the first time to serve as the electroactive probe as well as the carrier of secondary antibodies (Ab 2 ). Compared to bulk g-C 3 N 4 , mpg-C 3 N 4 possesses larger specific surface area, smaller electrochemical resistance and abundant active sites. So the proposed electrochemical immunosensor exhibited amplified detective signals which realized the sensitive detection of ALVs-J. Under the opitimized conditions, the immunosensor exhibited outstanding analytical performance for the detection of ALVs-J whose titer ranged from 10 2.08 to 10 4.0   TCID 50 /mL (TCID 50 : 50% tissue culture infective dose) with a low detection limit of 120 TCID 50 /mL (S/N   =   3). The sensitivity of the immnosensor was 6.15   μA/(TCID 50 /mL). This high sensitive immunosensor also displayed good selectivity, reproducibility and stability. Last but not least, this new strategy may be of great promise for clinic application in the future.