Au Nanoparticle-Based Integrated Microfluidic Plasmonic Chips for the Detection of Carcinoembryonic Antigen in Human Serum

A nanoplasmonic biosensor with merits of label-free and rapid detection provides a key tool for the detection of cancer markers in ultralow concentrations. Herein, a localized surface plasmon resonance (LSPR) biosensor integrated with microfluidics, which has multiple sensing units, was developed by nanomaterial fabrication technology. The performance of the LSPR biosensor was experimentally explored using nine clinical sample tests after the biofunctionalization of Au nanoparticles by biomodification and verified by four characterization methods. The linear detection response of carcinoembryonic antigen (CEA) appeared in the range of 0.5–100 ng/mL, with a detection limit below 1 ng/mL. The results illustrated that the LSPR platform improves the signal-to-noise ratio by about 85 times after adjusting testing system parameters. Furthermore, the simultaneous detection results of the proposed biosensor in nine serum samples of 50 μL from breast cancer patients were proved to be consistent with enzyme-linked immunosorbent assay (ELISA) results (r = 0.94). The low cost and remarkable performance of this LSPR biosensor make it promising to develop a precise clinical detection platform for auxiliary diagnosis, condition monitoring, and efficacy evaluation of cancer.