Ti3C2Tx-Au hybrid composites-based electrochemical biosensors for calreticulin biomarker detection

Abstract

A sensitive biosensor is critical for early breast cancer treatment and prognosis. Herein, a label-free electrochemical immunosensor is proposed for the sensitive detection of calreticulin (CALR), a new breast cancer biomarker. The biosensor relied upon an electroactive hybrid of ultra-thin Ti3C2Tx nanosheets preadsorbed with Au NPs and methylene blue (MB)(MB–Ti3C2Tx–Au), which served as redox-active centers and an electroactive probe to detect CALR biomarkers respectively. The detection mechanism followed a simple inhibition strategy, where the optimal differential pulse voltammetry (DPV) response of preadsorbed MB over the Ti3C2Tx–Au electrode decreased in proportion to the concentration of CALR biomarkers owing to the formation of the antibody-antigen immunocomplex. The biosensor could detect CALR-biomarker in the concentration range of 0.0015 to 0.94 ng mL−1 with a limit of detection (LOD) of 0.28 pg mL−1 and showed excellent antifouling properties against commonly encountered biomolecules such as hemoglobin (Ig), immunoglobulin G (IgG), neuron-specific enolase (NSE), and tumor necrosis factor-alpha (TNF). The proposed strategy provides an efficient method for utilizing MXene nanosheets to construct advanced biosensors with promising clinical applications.