A dual-quenching electrochemiluminescence immunosensor based on ABEI@Fe3O4@PDA-PdPt and Cu2−xS nanoflowers for sensitive detection of galectin-3

A ROS-competitive dual-potential ratiometric ECL immunosensor for ultrasensitive CA15-3 detection based on boron-doped defective NiSe catalysts.

Conventional luminol-based electrochemiluminescence (ECL) systems are constrained by low luminescence efficiency and stability, largely due to unstable hydrogen peroxide and inefficient dissolved oxygen conversion to reactive oxygen species (ROS). Here, the oxygen evolution reaction (OER) is harnessed to supply abundant ROS, which not only enhances the anodic ECL of luminol but also enables stable cathodic emission from CdSe quantum dots (QDs). To address these issues and circumvent false positive/negative signals common in ECL assays, a novel dual-potential ratiometric ECL sensor based on a competitive ROS mechanism was developed for the ultrasensitive detection of carbohydrate antigen 15-3 (CA15-3). A boron-doped and selenium vacancy-modified nickel selenide/poly(5-aminoindole) (Bx-NiSe/P5AIn) nanocomposite was first synthesized, which synergistically boosts OER catalytic activity through non-metal doping and defect engineering, thereby significantly amplifying the anodic ECL signal of luminol via ROS generation. Upon recognition of the target antigen, CdSe QDs labeled on the secondary antibody competitively consume ROS, leading to the enhancement of cathodic ECL and the attenuation of the anodic signal, thus establishing a ratiometric response model. The sensor exhibits a wide linear range from 0.001 to 100 U mL-1 for CA15-3 with a detection limit as low as 0.0003 U mL-1, demonstrating substantially improved sensitivity over conventional methods. This work not only provides an effective tool for early screening and diagnosis of breast cancer, but also opens a new avenue for designing multi-signal ECL sensing systems through catalysis-competition regulatory mechanisms.

Nanozyme-catalyzed dual-potential electrochemiluminescence immunosensor for simultaneous detection of CEA and NSE as lung cancer biomarkers.

Creating a dual-target detection system capable of independent signal output holds potential for enhancing the analytical reliability of biomarker detection, which may aid in early-stage cancer screening. Herein, a nanozyme-catalyzed dual-potential electrochemiluminescence (ECL) immunosensor was described for the simultaneous detection of lung cancer biomarkers: carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE). Au-luminol functionalized CoFe2O4 nanoflowers (CoFe2O4@Au-luminol) served as the anodic probe, while CdS quantum dot-decorated hollow CeO2 nanospheres (CeO2@CdS QDs) constituted the cathodic probe. CoFe2O4 and CeO2 featuring multivalent elements (Co2+/3+, Fe2+/3+, Ce3+/4+), with their exceptional peroxidase (POD)-like activity, drove H2O2 co-reactant decomposition into abundant hydroxyl radicals (•OH) and superoxide anions (O2•-), thereby boosting dual-potential ECL signals. Changes in the ECL responses at two different excitation potentials allowed CEA and NSE to be determined on the nanozyme-assisted immunosensor surface, respectively. The assay exhibited a linear range of 0.005-100 ng/mL, with detection limits of 0.87 pg/mL for CEA and 0.41 pg/mL for NSE. The nanozyme-enhanced ECL biosensing platform, characterized by superior specificity, stability, and practicability, offers significant potential for detecting multiple biomarkers.

A versatile AuNPs@UiO-66-based electrochemiluminescent immunosensing platform for sensitive detection of talin proteins

Dual-mode electrochemiluminescence and colorimetric detection of malathion based on a bifunctional rGO@ZnO/Zn-Fe3O4 nanozyme

A Bifunctional CoFcMOF Nanozyme Enables Dual-Mode PEC-Colorimetric Immunosensing of C-Reactive Protein with Built-In Cross-Validation.

A copper-based MOF as both electrochemiluminescence emitter and dual coreactant accelerator for ultrasensitive immunosensing of Cyfra 21 − 1 via quenching by polydopamine