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

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.