LAUSR

A new type of sandwich electrochemiluminescence (ECL) immunosensor was designed depended on ECL resonance energy transfer (ECL-RET) to achieve sensitive detection of procalcitonin (PCT). In brief, carbon nanotubes (CNT) and Au nanoparticles-functionalized graphitic carbon nitride (g-C3N4-CNT@Au) and CuO nanospheres covered with polydopamine (PDA) layer (CuO@PDA) were synthesized and applied as ECL donor and receptor, respectively. g-C3N4-CNT nanomaterials were in-situ prepared based on π-π conjugation, and the CNT content in the composite were optimized to achieve a strong and stable ECL signal. At the same time, Au nanoparticles were used to functionalize g-C3N4-CNT to further increase the ECL intensity and the loading amount of primary antibody (Ab1). Moreover, CuO@PDA was firstly used to successfully quench the ECL signal of g-C3N4-CNT@Au. Under the optimum experimental condition, the linear detection range for PCT concentration was with 0.0001 to 10 ng mL-1, and the detection limit was 25.7 fg mL-1 (S/N = 3). Considering prominent specificity, reproducibility and stability, the prepared immunosensor was used to assess recovery rate of PCT in human serum according to the standard addition method and the result was satisfactory. In addition, it's worth mentioning that a novel ECL-RET pair of g-C3N4-CNT@Au (donor)/CuO@PDA (acceptor) was firstly developed, which offered an effective analytical tool for sensitive detection of biomarkers in early disease diagnostics.