Electrochemical Immunosensor for Human Immunodeficiency Virus p24 Antigen Based on Mercapto Succinic Acid Hydrazide Copper Monolayer Modified Gold Electrode

An immunosensor based on mercapto succinic acid hydrazide copper (II) (CuL) monolayer modified gold electrode (Au|CuL) was developed for the determination of human immunodeficiency virus p24 antigen in acquired immunodeficiency syndrome patients' serum. CuL displays reductive electrocatalyzation for H2O2 and can be employed as electron transfer media between HRP and electrode. Based on a competition immunoreaction, a differential pulse voltammetric determination method for p24 antigen was established by the peak current increase of the immobilized CuL. The current increase results from the enhanced catalytic current of H2O2 reduction with the help of HRP labeled immunocomplex. The free immunocomplex was produced by competitive binding to the limited amount of HRP labeled p24 antibody (HRP-anti p24) from the p24 in sample solution and immobilized on the bottom of the detective hole. The proposed method needs neither separation nor washing up step, which simplifies the immunoassay procedure and shortens the analytical time. The method provides a new promising platform for diagnosing the AIDs disease.