A novel binary luminophore based high-efficient electrochemiluminescence biosensor for ultrasensitive detection of human epidermal growth factor receptor-2

For the first time, a high-efficient and low-cost electrochemiluminescence (ECL) biosensor was constructed for ultrasensitive detection of breast cancer related human epidermal growth factor receptor-2 (HER-2) using a novel binary luminophore and low concentration of coreactant. Firstly, Au nanoparticles decorated graphite-like carbon nitride (g-C3N4@Au) was designed as sensing platform, which can generate ECL signal in the potential range from -1.2 V to 0 V when peroxydisulfate (S2O82-) was used as the coreactant. Secondly, amino-modified capture probes (CP) were immobilized on the surface of g-C3N4@Au via Au-N bonds. In addition, Zr-based metal organic framework (Zr-MOF) modified bulk boron carbon oxynitride (BCNO), named ZMB, exhibited remarkable ECL intensity at the potential window of -2.0 V to 0 V with 0.8 mM S2O82-. ZMB possessed a large specific surface area and abundant amino groups to anchor Au@Pt nanoparticles (Au@PtNPs). Therefore, HER-2 binding aptamers (HBA) could be anchored on Au@PtNPs to form the tracer label. Under optimal conditions, the proposed ECL biosensor displayed a wide linear range from 10 fg mL(-1) to 100 ng mL(-1) with a limit of detection (LOD) as low as 0.2 fg mL(-1). Importantly, this work utilized ZMB/S2O82- as new ECL system with satisfactory detection performances, which provided a potential approach to improve the sensitivity in clinical diagnosis.