Metal composite oxides Bi₂MoO₆/IL membrane as matrix for constructing ultrasensitive electrochemical immunosensor

In the process of diagnosis and disease monitoring, it is important to quickly and easily detect protein biomarkers. The strategy reported here is an attempt to prepare Bi₂MoO₆ nanomaterial with new three-dimensional holes morphology surrounded by rod and sheet to construct a simple and sensitive sensing platform, where Bi₂MoO₆/ionic liquid (IL) composite was modified on the carbon paste electrode (CPE). In order to monitor the assembly process of human IgG immunosensors, a plurality of electrochemical tests such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) was executed. The obtained BSA/anti-IgG/GA/Bi₂MoO6/IL-CPE displayed prominent conductivity and high sensitivity in detecting human immunoglobulin G (human IgG). Under the optimal experimental conditions, the results by differential pulse voltammetry (DPV) showed that the constructed label-free IgG immunosensor can detect IgG in the range of 0.01 to 1000 ng mL^-1, and limit of detection (LOD) was 4 pg mL^-1. The immunosensor displayed good performances including selectivity, reproducibility, and stability. Based on preliminary experiments, Bi₂MoO₆ and its composite materials are very promising for the construction of a variety biosensors for the analysis of other biological substances. Graphical abstract.