Label-free electrochemical immunosensor based on conductive Ag contained EMT-style nano-zeolites and the application for α-fetoprotein detection

Early detection of tumor markers is of great significance, while the common used immunosensors always meet the contradiction between the conductivity and limited surface area for immobilizing more antibodies. Herein, to address this problem, the conductive silver containing EMT zeolite nanoparticles (NPs) were prepared by ion exchange and further applied in Alpha-fetoprotein (AFP) detection. Since no template was involved in the nanosized EMT zeolite synthesis at low temperature, excessive silver ions can be introduced inside the channels of zeolite and bring greatly enhanced conductivity. Besides the native porous feature of zeolite, the silver containing EMT based immunosensors shows very good performance in AFP detection, which well compensates the conductivity and surface area. In human serum, the proposed immunosensor also shows linear and even higher response to AFP relative to that in PBS. This kind of zeolite based immunosensor protocol is potentially attractive for clinical immunoassay.