Highly Efficient PTCA/Co3O4/CuO/S2O82– Ternary Electrochemiluminescence System Combined with a Portable Chip for Bioanalysis

Herein, we reported an efficient electrochemiluminescence (ECL) biosensor chip for sensitive detection of neuron-specific enolase (NSE). First, 3,4,9,10-perylenetetracarboxylic acid with good luminescence characteristics was used as a luminophore to obtain a stable ECL signal. Subsequently, hollow porous Co3O4/CuO concave polyhedron nanocages (CPNCs) were designed as co-reaction promoters to amplify the luminescence signals for highly sensitive trace detection of NSE. In brief, the rapid cyclic conversion of Co3+/Co2+ and Cu2+/Cu+ redox pairs could continuously catalyze the reduction of persulfate (S2O82-), thus providing a large number of essential active intermediates (SO4•-) for ECL emission. Meanwhile, the unique structure of Co3O4/CuO CPNCs possessed a large specific surface area, which greatly improved its catalytic efficiency. Third, NKFRGKYKC was developed as an affinity ligand for specific antibody fixation, which improved incubation efficiency and protected bioactivity of antibodies. Finally, we independently designed a microchip and applied it for ECL detection to improve the practical application ability of the sensor. The developed biosensor exhibited good sensitivity with a wide linear range (10 fg/mL to 100 ng/mL) and a low detection limit (3.42 fg/mL), which played an active role in the clinical application of sensing analysis.