Mechanistic insights into persulfate-driven electrochemiluminescence amplification enabled by a Ru@Cu-MOGs/Zr-CeO2-Ag hybrid system.

Ultrasensitive cathodic electrochemiluminescence immunoassay for C-reactive protein enabled by boron-doped diamond electrodes and quantum dot nanospheres.

Immunosensors for dual tumor biomarker detection based on ternary electrochemiluminescence using confined CeO2 nanozyme as Co-reactant enhancers for luminol-O2 system.

Electrochemiluminescent (ECL) biosensing is fundamentally limited by inefficient coupling between catalytic radical generation and luminophore excitation. Here, we report an amino acid-programmed biomineralization strategy for constructing radical-proximal enzyme-MOF interfaces under mild aqueous conditions. Serine reconfigures zirconium precursor chemistry to convert a charge-mismatched mineralization process into a charge-adaptive one, enabling biomineralization of cationic horseradish peroxidase (HRP) within PCN-224. The resulting HRP@PCN-224(Ser) exhibits enhanced enzyme loading, preserved protein structure, improved catalytic competence, and pronounced solvent tolerance. Mechanistic analyses indicate that serine-mediated mineralization does more than facilitate enzyme incorporation: it creates a spatially integrated microenvironment in which H2O2 activation and ZnTCPP excitation are more effectively coupled, leading to enhanced ECL transduction. Accordingly, HRP@PCN-224(Ser) produces an approximately 9-fold stronger ECL response than the serine-free counterpart in the presence of H2O2. Integrated with a dual-aptamer signal-off format, this interface enables ECL sensing of influenza H1N1 hemagglutinin (HA) over 0.1-1000 ng mL-1 with a detection limit of 0.03 ng mL-1, together with good selectivity and satisfactory recovery in serum samples. These findings establish amino acid programmed biomineralization as an interfacial design strategy for enzyme-MOF integration and provide a mechanistically grounded framework for improving ECL bioanalysis through radical-proximal transduction.

Herein, a novel silver nanocrystal-patterned (Ag-NCP) metasurface-based electrochemiluminescence (ECL) sensor for the detection of miRNA-92a-3p in extracellular vesicles (EVs) was constructed with a luminescent 2,2'-bipyridine-5,5'-diamine (Bpy)-covalent organic framework (COF). On the basis of the soft-template and spatial confinement effects of micelles, the ordered nucleation and growth of Ag NCs finally yielded an Ag-NCP metasurface with synergistic structure characteristics of a long-range ordered arrangement and a short-range disordered morphology. Long-range order was defined as the uniform and periodic spatial arrangement of Ag NCs over macroscopic dimensions, which was characterized by a stable and regular structural organization. By comparison, short-range disorder refers to the irregularity in the size, surface morphology, and spacing of adjacent Ag NCs on the local nanoscale with random and variable features. The short-range disordered morphology of irregular Ag NCs in the metasurface generated high-density electromagnetic hotspots due to the localized surface plasmon resonance and the surface plasmon-coupling effect. It greatly enhanced the local electromagnetic field and triggered the Purcell effect, thereby accelerating the luminescence process and improving the ECL efficiency of the Bpy-COF. Moreover, the long-range-ordered arrangement of Ag NCs formed a dense electromagnetic network in the Ag-NCP metasurface to improve the stability and persistence of luminescent signals. The constructed Ag-NCP metasurface-based ECL sensor was successfully applied to the detection of miRNA-92a-3p with a linear range of 1 fM to 10 nM and a limit of detection of 0.36 fM. This biosensor was employed successfully for the detection of miRNA-92a-3p in ascites from gastric cancer patients, which can serve as an auxiliary diagnostic tool.

Advances in ultrasensitive immunoassays have enabled reliable quantification of neuroglial biomarkers in blood, providing valuable insights into neurological disorders. However, cross-platform evaluations are necessary to ensure comparability and standardization. This study aimed to compare the analytical performance of a Single Molecule Array (Simoa) and an ultrasensitive electrochemiluminescence (ECL) assay for quantifying neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in human serum. Baseline serum samples from 174 participants in the RIFUND trial were analyzed in parallel on both platforms. Concentrations of NfL and GFAP were compared using Spearman correlation, Bland-Altman analyses, reproducibility assessments, dilution linearity, and cross-platform recovery. All samples were quantifiable on both platforms. NfL concentrations correlated strongly between methods (Spearman correlation r = 0.88, p < 0.0001), whereas GFAP correlated moderately (r = 0.77, p < 0.0001). Inter- and intra-assay coefficients of variation were comparable between platforms for both analytes. The relationship between the two assays could be described with the following equations: NfLECL = 7.63 × NfLSIMOA + 1.71 and GFAPECL = 0.332 × GFAPSIMOA + 4.22. Dilution linearity was excellent on both platforms (R2 > 0.99), although cross-platform recovery varied systematically across the analytical range. Both Simoa and ECL demonstrated strong analytical performance for neuroglial biomarker quantification in serum. Despite systematic differences in absolute concentrations, relative agreement was high, particularly for NfL. These findings highlight the need for platform harmonization and provide empirically derived conversion factors to support analytical comparability in research and clinical applications.

Herein, we report a novel and highly sensitive electrochemiluminescence (ECL) sensor for the detection of permethrin (PT). This sensor is constructed based on a nanocomposite in which luminol-reduced gold nanoparticles (Lu-Au NPs) are anchored onto a nickel-based metal-organic framework (Ni-MOF). The nanocomposite (Lu-Au@Ni-MOF) possesses a three-dimensional porous and microflower-like architecture, offering an exceptionally high surface area that facilitates the immobilization of Lu-Au NPs, thereby maximizing the loading of the luminol emitter. The detection of PT is based on the quenching of the luminol ECL signal mediated by PT. Under the optimized conditions, the sensor exhibits a wide linear response for PT from 5.0 × 10-9 to 5.0 × 10-5 mol L-1, with a remarkably low detection limit of 1.8 × 10-10 mol L-1. The practical reliability of the sensor was validated through the determination of PT in commercial pesticide formulations. This cost-effective and robust approach demonstrates significant potential for practical, on-site monitoring of pesticide pollutants.

The electronic metal-support interaction (EMSI) modulates the electronic structure and activity of catalysts, yet its role in electrochemiluminescence (ECL) remains unclear. Using graphene-supported Pd nanoparticles, we show that EMSI downshifts the Pd d-band center and that charge transfer between Pd and graphene facilitates both luminol oxidation and H2O2 decomposition, significantly enhancing the ECL signal.

Here, an electrochemiluminescence (ECL) imaging technique in gel is established to visualize single ruthenium-labeled brain tissue sections using a coreactant (e.g., tripropylamine, TPA) filled agarose hydrogel, instead of the coreactant in solution. The confined space between the gel and the tissue section restricts the diffusion of intermediates during the ECL reaction, resulting in enhanced and localized ECL emission, thereby improving the microstructural resolution. Accordingly, spatial heterogeneity in the ECL signals on the mouse midbrain tissue sections was observed, which primarily results from the selective impact of intrinsic tissue structural differences on the local diffusion-limited microenvironment under gel confinement. Consequently, this gel-confined ECL imaging technique can directly translate the intrinsic biophysical differences in neuroanatomy into quantifiable imaging signals without relying on complex immunohistochemical staining or high-resolution optical systems. Furthermore, the imaging method in gel offers relatively good stability over days and repeated imaging. These advantages lay the groundwork for future long-term sample preservation and potential clinical applications.

An ECL immunosensor based on the synergistic self-enhancement of CuCoFe-LDH with Luminol-PEI for ultrasensitive detection of AFP.

Accurate monitoring of microcystin-LR (MC-LR) in complex water matrices is critical for environmental safety but remains challenging due to the limited sensitivity and stability of traditional methods. Conventional electrochemiluminescence (ECL) emitters often suffer from aggregation-caused quenching (ACQ) in aqueous environments. To overcome this, we engineered a highly efficient aggregation-induced electrochemiluminescence (AIECL) emitter using a supramolecular confinement strategy. A shape-tunable supramolecular organic framework (SOF), tetrakis(1-carboxyethylpyridinium) tetraphenylethylene derivative@cucurbit[8]uril (TPE-CEPy@CB[8]), was constructed via host-guest interactions, which enhanced ECL efficiency by restricting the intramolecular motion (RIM) of the luminophore. Based on this SOF, a robust "on-off-on" biosensor was developed utilizing ECL resonance energy transfer (ECL-RET). The system incorporated target-triggered entropy-driven DNA amplification (EDA) and a Zn2+-activated DNAzyme, enabling simultaneous signal amplification and DNA recycling. Operational feasibility was confirmed through ECL images, which allowed intuitive visualization of concentration-dependent ECL variations, thereby achieving dual-readout detection based on both signal intensity and images analysis. Under optimal conditions, the biosensor demonstrated a broad dynamic range from 0.01 to 100.0 ng mL-1, with ultralow detection limits of 1.35 pg mL-1 via ECL intensity detection and 1.45 pg mL-1 via ECL images analysis. Crucially, the method demonstrated excellent accuracy in real environmental waters, with results highly consistent with standard high-performance liquid chromatography (HPLC) analysis. This work presents a superior dual-readout AIECL strategy that effectively mitigates matrix interference, providing a reliable avenue for the precise monitoring of trace environmental pollutants.

Broadly neutralizing antibodies (bNAbs) are a promising HIV prevention strategy due to their potent antiviral activity and potential for long-acting protection. While the vaginal microbiome can influence mucosal immunity and the efficacy of topical interventions, its effect on the pharmacokinetics of systemically administered bNAbs remains unclear. Forty-two women were included in a retrospective analysis of the CAPRISA 012B clinical trial evaluating passive immunization for HIV prevention. Vaginal microbiota were profiled using 16S rRNA gene sequencing and classified into three community state types (CSTs): CST I (Lactobacillus crispatus-dominated), CST III (Lactobacillus iners-dominated), and CST IV (diverse, non-Lactobacillus-dominated). Mucosal concentrations of CAP256V2LS were measured from Soft-cup® cervicovaginal fluid using the Meso Scale Discovery (MSD) platform with electrochemiluminescence (ECL) detection. Longitudinal analyses assessed CST stability, transitions, and associations with mucosal antibody pharmacokinetics. Lactobacillus-dominated CSTs were most frequent (CST I, 5.3%; CST III, 57.9%), whereas BV-associated CST IV subtypes were less common (CST IV-A, 2.6%; CST IV-B, 34.2%). Lactobacillus-dominated communities were generally stable, while high-diversity CST IV communities were more dynamic, with transitions toward Lactobacillus-dominated states observed over time. Despite these microbial shifts, mucosal bNAb kinetic patterns appeared broadly similar across CSTs. Within the limits of this exploratory analysis, we did not observe clear evidence of an association between CST composition and the timing or magnitude of mucosal bNAb accumulation. These observations were descriptive and not derived from inferential statistical or pharmacokinetic modelling analyses. In this exploratory sub-analysis, cervicovaginal microbiome composition was not clearly associated with differences in mucosal concentrations of systemically administered bNAbs. These findings suggest that systemic bNAb delivery may achieve measurable genital tract exposure across diverse vaginal microbial communities; however, larger studies incorporating inferential pharmacokinetic and immunological analyses are needed to confirm these observations and exclude subtle microbiome-associated effects.

Understanding the nature of electrode-electrolyte interface remains a long-sought goal in electrochemistry, as it could help to address major societal challenges of our time, such as the global energy and environmental crisis. Electrochemiluminescence (ECL) imaging enables the direct visualization of the electrode-electrolyte interface, rather than inferring active sites from morphology or surface chemistry. However, the signal decay and limited stability of ECL signals restrict their practical application. Here, by utilizing the high-frequency pulsed output of a triboelectric nanogenerator (TENG), we developed a TENG-based electrochemiluminescence (TECL) imaging inspired by the cardiac diastole-systole cycle. The TECL signal overcomes the limitations of traditional ECL and employs a zero-shot deconvolution network (ZS-DeconvNet) to achieve super-resolution TECL (ZSSR-TECL) imaging. Utilizing the ZSSR-TECL imaging, the catalytic regions at the electrode-electrolyte interface can be analyzed, with high-activity, moderate-activity, and degraded regions clearly distinguished. In addition, three methods have been established for analyzing the catalytic activity of the electrode-electrolyte interface, including direct observation of TECL images, analysis of signal intensity profiles, and quantification of total signal intensity in fixed regions. The TECL imaging has the potential to enable the research of electrode-electrolyte interfaces and offers a perspective for enhancing ECL imaging.

The content release of single giant liposomes (40-100 μm diameter) confined in a microfluidic device was investigated by combining amperometric, fluorescence, and electrochemiluminescence (ECL) monitoring techniques. Accordingly, a microfluidic device was designed to guide, isolate, and immobilize without altering a single liposome in contact with a semitransparent platinum electrode, in a micrometric channel compatible with luminescence microscopy observations. Sealed giant asymmetrical liposomes were made from DOPG/DOPC phospholipids (i.e., 1,2-dioleoyl-sn-glycerol-3-phospho-(1'-rac-glycerol) sodium salt/1,2-dioleolyl-sn-glycero-3-phosphocholine) trapping ECL reagents ([Ru(bpy)3]2+ luminophore and tri-n-propylamine coreactant). The liposome membrane permeation/rupture was triggered by polarization of the platinum electrode. Under these conditions, the liposomes content releases were simultaneously imaged and analyzed by ECL, photoluminescence, and amperometry. It was shown that ECL generation following liposome electroporation is governed not only by membrane permeabilization but critically by the convective transport of ECL reagents above the electrode interface. Emission was observed only upon rapid membrane rupture, which generates sufficient lateral convection to displace released reagents beyond phospholipid-blocked electrode regions. ECL imaging further reveals localized suppression of electrochemical activity due to phospholipid adsorption after rupture. Together, these findings establish convective transport as a key determinant of ECL detection at the single-liposome level in confined environments, with important implications for the electrochemical analysis of biological and artificial vesicles.

Pyrene (Py), an archetypal electrochemiluminescence (ECL) luminophore, suffers from inherent aggregation-caused quenching (ACQ) stemming from its planar π-conjugated structure and consequent intermolecular π-π stacking, severely restricting its practical utility. Herein, a gel confinement-induced emission enhancement (GCIEE) strategy is proposed to circumvent this limitation. At room temperature, 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H4TBAPy) underwent a coordination reaction with Tb3+ to rapidly construct a Py-based metal-organic gel (Py-MOG). The rigid coordination framework of Py-MOG imposed spatial confinement on Py ligands, effectively suppressing their detrimental ACQ effect and thereby dramatically boosting the ECL efficiency. Significantly, the as-prepared Py-MOG exhibited a strong and stable ECL emission at -1.65 V without coreactants, and its ECL efficiency achieved a 3.39-fold enhancement relative to the H4TBAPy monomer. As a proof of concept, microplastics (MPs), a kind of persistent micropollutants that threaten ecosystems and human health even at trace levels due to their bioaccumulation and toxicity, were selected as the model target for evaluating the application of Py-MOG in ECL sensing. By coupling Py-MOG with an aptamer recognition-initiated Cas12a thrusting strand displacement reaction (CtSDR) amplification, a biosensor was constructed for the sensitive detection of polyvinyl chloride (PVC) and polystyrene (PS), displaying the limits of detection of 5.2 μg/L for PVC and 7.5 μg/L for PS, respectively. The GCIEE strategy provides a rapid, simple, and novel method to significantly improve the ECL efficiency of Py-based luminophores. The self-luminous Py-MOG establishes an ultrasensitive ECL platform for MPs detection without exogenous coreactants.

Rapid and accurate measurement of host-guest binding constants is crucial for constructing supramolecular assemblies. However, conventional spectroscopic titration methods require high sample consumption, involve lengthy workflows, and demand specific optical properties. Here, we propose a superoxide-triggered luminol electrochemiluminescence (ECL) platform for fast, sensitive, and broadly applicable screening of binding constants in viologen derivative-based supramolecular assemblies. It is disclosed that viologen derivatives could significantly promote luminol ECL by accelerating oxygen reduction and stabilizing the superoxide anion radical at the electrode interface through electrostatic interactions. Upon host-guest complexation, the concentration of active viologen monomers decreased, leading to a measurable reduction in the ECL enhancement. Notably, the ECL intensities of various assemblies exhibited a strong correlation with their binding constants, enabling direct affinity evaluation without the need for traditional UV-vis or fluorescence titration. This work confirms that superoxide-triggered luminol ECL is able to act as a powerful analytical tool for supramolecular screening, offering substantial advantages in speed, sensitivity, and generality.

Covalent organic frameworks (COFs) have garnered increasing attention in electrochemiluminescence (ECL), but how to improve ECL efficiency is still challenging due to the insufficient charge separation driving forces and non-directional charge transfer. Herein, by rationally modulating the types of building blocks, we synthesize two donor-acceptor (D-A) imine-linked COFs with distinct charge transfer directionality (namely Btt-Tpa-COF and Btt-Tapt-COF). In Btt-Tapt-COF, the D-A orientations of building units align with those of imine bonds (Cδ+=Nδ-), which facilitates the establishment of codirectional charge transfer channels and significantly promotes the intramolecular charge separation/transport for the achievement of exceptional ECL performance. In contrast, Btt-Tpa-COF exhibits the reduced ECL stability and efficiency due to its reversed D-A orientation that impedes the intramolecular charge transfer. As a proof of concept, we construct a target-responsive ECL aptasensor to measure lincomycin (LIN) with Btt-Tapt-COF as an efficient emitter and the three-dimensional DNA hydrogel as an intelligent signal switch. This aptasensor can sensitively measure LIN within a large linear response range of 0.0001-10 ng/mL. Importantly, this research reveals the effect of charge transfer directionality on ECL performance and provides a promising strategy for the construction of efficient ECL sensors to quantify antibiotics in food and the environment.

Luminescent hydrogel-enabled electrochemiluminescent aptasensor and portable analyzer for on-site quantification of acetamiprid in vegetables.

Electrochemiluminescence (ECL) is a powerful tool for clinical diagnosis due to its exceptionally sensitive characteristics. In this work, enhanced and stable anodic ECL was observed in the suspension of hydrothermally synthesized molybdenum disulfide quantum dots (MoS2 QDs) and ruthenium(II) tris(2,2'-bipyridyl) (Ru(bpy)32+), which was enhanced more than 80-fold compared to that of individual Ru(bpy)32+. MoS2 QDs can effectively catalyze the oxidation of Ru(bpy)32+, with amino groups on their surface serving as coreactants. As a result, MoS2 QDs exhibit high efficiency comparable to tripropylamine (TPrA) for the ECL of Ru(bpy)32+. The possible mechanism of the electrode surface reaction was discussed, while several factors including the pH of the buffer solution and the amount of MoS2 QDs were also investigated, to further confirm the role of MoS2 QDs in the Ru(bpy)32+/MoS2 QDs system. Based on the quenching effect between the excited state of Ru(bpy)32+ in the Ru(bpy)32+/MoS2 QDs ECL system and the oxidized form of dopamine (DA), a DA sensing platform was successfully established, and the DA content in urine was successfully detected (recovery rate: 95.90-101.13%).

Early and sensitive diagnosis is critical for improving the survival rate of breast cancer patients. However, the early detection of triple-negative breast cancer (TNBC) remains a significant challenge due to the lack of specific biomarkers. Herein, we developed a four-channel asymmetric bipolar electrode (BPE)-based microfluidic chip for the highly sensitive and multiplexed profiling of breast cancer exosomes. By leveraging the spatial separation of the capture end (cathode) and the signal end (anode) in a closed BPE configuration, this chip enables efficient on-chip capture of tumor exosomes and labeling with electrochemical probes at the cathode. The resulting faradaic current is coupled to drive the electrochemiluminescence (ECL) of luminol at the anode, allowing for simultaneous quantification of multiple surface markers on exosomes. The BPE features a fan-shaped asymmetric design, in which the enlarged cathode area increases exosome capture capacity, while the confined anode area enhances local current density, thereby significantly boosting the detection sensitivity. Furthermore, this fan-shaped geometry promotes a stable potential distribution and facilitates the integration of a multi-channel array for synchronous detection of multiple biomarkers. The sensing platform achieved an ultra-low detection limit of 1.39 particles per μL for exosomes derived from MDA-MB-231 cells, with a linear range spanning three orders of magnitude. Multiplexed analysis of surface marker expression on exosomes from three cell lines, i.e. MDA-MB-231 (TNBC), MCF-7 (luminal A breast cancer), and MCF-10A (normal mammary epithelial cells), demonstrated that the combined biomarker profile significantly improved the accuracy of discriminating exosomes from different cancer cells. Finally, the method was successfully applied to analyze exosomes in human serum, accurately distinguishing patients with TNBC from those with luminal A breast cancer and from healthy individuals. Overall, this strategy enhances sensitivity via asymmetric BPE design, achieving LODs of 1.39-2.22 particles per μL, and improves classification accuracy through multiplexed detection with AUC values of 0.93-1.00, offering a powerful tool for early screening and molecular subtyping of breast cancer.