Highly Efficient Dual-Polar Electrochemiluminescence from Au25 Nanoclusters: The Next Generation of Multibiomarker Detection in a Single Step

For the first time, simultaneous cathodic and anodic electrochemiluminescence (ECL) emissions of bull serum albumin stabilized Au-25 nanoclusters (Au-25 NCs) as highly efficient bipolar ECL probes were constructed for the single-step and synchronous determination of carcinoembryonic antigen (CEA) and mucin 1 (MUC1) based on different coreactant and coreaction accelerators. Under the potential cathodic scanning, TiO2 nanosheets (TiO2 NSs) as cathodic coreaction accelerators could catalyze the reduction of coreactant dissolved O-2 for promoting cathodic ECL emission of Au-25 NCs, while, under the potential anodic scanning, Cu2O@Cu nanoparticles (Cu2O@Cu NPs) as anodic coreaction accelerators could stimulate the oxidation of coreactant N,N-diethylethylenediamine (DEDA) for enhancing anodic ECL emission of Au-25 NCs. Thus, the proposed strategy easily solved one main technical challenge of cross reactions of dual-luminophors for dual-biomarker detection, resulting in great sensitivity and accuracy toward the detection of CEA down to 0.43 pg/mL and MUC1 down to 5.8 fg/mL. As a proof of concept, this work realized single-step and simultaneous detection of dual biomarkers, which initiates a new thought in realizing a new generation of dual-biomarker ECL detection beyond the traditional ones in sensing analysis and diagnostic sensing.