A dual-channel biomarker detection based on spatiotemporal upconversion-linked immunosorbent assay

Multiplexed detection of different but clinically relevant low-abundance biomarkers is of paramount importance for early-stage disease diagnosis. Herein, we have developed a simple, yet versatile and sensitive upconversion-based sensing platform that leverages the excitation-controlled switchable optical properties of upconversion nanoparticles to achieve the simultaneous detection of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) biomarkers. The assay yielded a limit of detection of 7.81 pg/mL for AFP and 1.02 x 10-4 IU/mL for hCG in spiked serum. By utilizing the dual-channel luminescent signals as dual input, we have further developed an open-source software for automatic risk assessment of testicular cancer based on a dual-input logic OR gate. Due to the high optical tunability of upconversion luminescence, the technique and software present in this work should inspire new ideas for the early diagnosis of a wide range of diseases.