Immunosensors offer great promise for cancer diagnostics owing to their high sensitivity, specificity, and potential for miniaturization. However, conventional electrochemical immunosensors often rely on single-step enzyme reactions and single-biomarker detection, limiting their signal amplification capacity and diagnostic accuracy for complex diseases such as prostate cancer. Here, we presented an ultrasensitive cascade enzyme immunoassay electrochemical microfluidic chip (CEE-CHIP) for the simultaneous detection of multiple prostate cancer biomarkers. The system employed primary antibody-functionalized magnetic metal-organic frameworks (Fe3O4@MOF), followed by target antigens binding specifically and glucose oxidase-labeled secondary antibodies conjugating to form stable sandwich immunocomplexes. The functionalized Fe3O4@MOF were magnetically positioned within a microfluidic channel and a subsequent cascade reaction involving glucose oxidase generates H2O2. H2O2 was detected by a Co3O4/MXene-modified working electrode, resulting in amplified electrochemical signals. This system allowed for the simultaneous detection of multiple tumor markers, including prostate-specific antigen and Engrailed 2, with detection limits as low as 0.154 and 0.146 pg/mL, respectively. With a broad linear range (0.001-100 ng/mL), excellent sensitivity, and minimal sample consumption, the CEE-CHIP represented a promising non-invasive, point-of-care diagnostic platform for early prostate cancer detection and broader clinical applications.
Ai et al. (Thu,) studied this question.