In order to solve the problems of unstable signal and fast decrease of response signal of traditional electroactive substances, we synthesized a new type of electroactive substances, so that they can cooperatively amplify the response signal of the immune sensor and further improve its sensitivity. The conductive organic ligand tetrahydroxy 1,4-benzoquinone (THQ) and Cu2+ were chelated to form a stable polymeric two-dimensional metal-organic framework material Cu-THQ. Cu-THQ is a new type of electroactive substance. Compared with the traditional electroactive substance, Cu-THQ not only has stronger Redox activity, but also better stability and biocompatibility. We carried out various electrochemical characterizations on Cu-THQ and further proved that the introduction of Cu2+ not only greatly enhanced the stability of THQ electrical signal, but also increased its signal response. The experimental results showed that the prepared immunosensor exhibited good linearity for the detection of carcinoembryonic antigen in the range 1 fg/mL to 40 ng/mL, with detection limits and sensitivity of 0.477 fg/mL and 14.81 µA/(ng/mL)/cm2, respectively.
Keywords: CEA; Cu-THQ MOFs; Electrochemical immunosensor; Square-wave voltammetry.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.