Search Results (109)

Electrochemiluminescence (ECL) biosensors based on aggregation-induced emission (AIE) emitters have recently emerged as highly sensitive tools for biosensing. The AIE phenomenon, characterized by a significant luminescence change upon aggregation due to restricted intramolecular rotation or vibration, effectively enhances ECL intensity and efficiency, endowing AIECL emitters with high selectivity and stability. This review provides an overview of the developmental trajectory of AIECL, systematically elaborates and comparatively analyzes the mechanisms and luminophore systems of conventional ECL and AIECL, discusses the design strategies and construction methods of AIECL luminophores, and comprehensively summarizes the innovative applications of AIECL in the realm of biosensors. Finally, some of the current challenges in this emerging field are outlined, along with perspectives on future trends. Full article

To address the challenges of nonspecific adsorption interference and low mass transfer efficiency encountered by electrochemiluminescence (ECL) sensors in complex biological matrices, this study developed a Mn@CeO₂ nanozyme-based sensing interface. The Mn-doped CeO₂ enhanced electron transfer efficiency, increased oxygen vacancy concentration, and stabilized the Mn-O-Ce structure, collectively enabling highly efficient peroxidase (POD)-like activity. The design significantly improved ECL reaction efficiency, which simultaneously conferred synergistic antifouling and mass transport enhancing properties. The mesoporous silica nanoparticle on the sensing interface accelerated mass transfer processes, thereby overcoming the limitations of traditional diffusion-controlled kinetics. The Mn@CeO₂ nanozyme and mesoporous silica nanoparticle synergistically improved electron transfer and reactant enrichment, thereby significantly enhancing the signal response. Concurrently, a biomimetic anti-fouling coating was introduced at the interface to effectively suppress nonspecific adsorption of interferents. The constructed nanozyme-enhanced ECL sensing platform was demonstrated through the detection of dopamine (DA) as a model neurotransmitter, exhibiting favorable detection performance while maintaining high-accuracy detection in complex biological samples. This strategy offers a novel approach to developing highly sensitive and interference-resistant ECL sensors, with promising applications in disease biomarker monitoring and live physiological sample analysis. Full article

Glucose (Glu) detection, as a fundamental analytical technique, has applications in medical diagnostics, clinical testing, bioanalysis and environmental monitoring. In this work, a solid-phase electrochemiluminescence (ECL) enzyme sensor was developed by immobilizing the ECL emitter in a stable manner within bipolar silica nanochannel array film (bp-SNA), enabling sensitive glucose detection. The sensor was constructed using an electrochemical-assisted self-assembly (EASA) method with various siloxane precursors to quickly modify the surface of indium tin oxide (ITO) electrodes with a bilayer SNA of different charge properties. The inner layer, including negatively charged SNA (n-SNA), attracted the positively charged ECL emitter tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺) via electrostatic interaction, while the outer layer, including positively charged SNA (p-SNA), repelled it, forming a barrier that efficiently concentrated the Ru(bpy)₃²⁺ emitter in a stable manner. After modifying the amine groups on the p-SNA surface with aldehyde groups, glucose oxidase (GOx) was covalently immobilized, forming the enzyme electrode. In the presence of glucose, GOx catalyzed the conversion of glucose to hydrogen peroxide (H₂O₂), which acted as a quencher for the Ru(bpy)₃²⁺/triethanolamine (TPA) system, reducing the ECL signal and enabling quantitative glucose analysis. The sensor exhibited a wide linear range from 10 μM to 7.0 mM and a limit of detection (LOD) of 1 μM (S/N = 3). Glucose detection in fetal bovine serum was realized. By replacing the enzyme type on the electrode surface, this sensing strategy holds the potential to provide a universal platform for the detection of different metabolites. Full article

The dual-signal output self-calibration mode reduces the false positive and negative signals of electrochemiluminescence (ECL) aptamer sensors. A competitive dual-signal ECL platform was designed for the ultrasensitive detection of kanamycin (KAN) using a zirconium metal–organic framework (Zr MOF) and Luminol as ECL emitters. To enhance the ECL efficiency, a co-reactant (polyethyleneimine, PEI) was covalently bound to the Zr MOF to achieve self-enhanced ECL. Based on the selective interaction between KAN and its aptamer, the Luminol/KAN/Zr MOF-PEI “sandwich” structure was immobilized on the electrode surface. The competition for PEI between emitters increased the Luminol ECL signal and decreased the Zr MOF’s ECL signal. The ratio in ECL signals between the two competitive emitters enabled the quantitative analysis of KAN, achieving a detection limit as low as 7.86 × 10⁻⁴ ng/mL. This study elucidated the synergistic mechanism between self-enhanced ECL and ECL competition, offering a novel approach for constructing dual-signal ECL sensors using a single co-reactant. Full article

Electrochemiluminescence (ECL)/electrochemistry (EC) dual-mode sensors have garnered significant interest for their enhanced analytical reliability through the cross-verification of dual-signal outputs. However, conventional approaches necessitate two potential scans to acquire ECL and EC signals independently, resulting in temporal and environmental discrepancies between the two detection modes. In this paper, we present a novel synchronous ECL/EC dual-mode sensing platform for lead ion (Pb²⁺) detection via a one-step potential scan (0.2 to −0.4 V vs. Ag/AgCl) utilizing a G-quadruplex (G4)–hemin DNAzyme complex. This complex synergistically catalyzed the electrochemical reduction of dissolved oxygen, concurrently generating a distinct cathodic ECL emission from Ru(bpy)₃²⁺ and a synchronous reduction current peak at −0.25 V. Pb²⁺ quantification was achieved through its dose-dependent suppression of DNAzyme activity by destabilizing the G4–hemin interaction, thereby proportionally attenuating both ECL intensity and EC signal (reduction current). The integrated sensor demonstrated high sensitivity (detection limits of 1.51 nM for ECL detection and 2.03 nM for EC detection), robust anti-interference capability, and satisfactory reproducibility, with recoveries ranging from 95.5 to 103.1% in environmental water analysis. This work established a paradigm for one-step dual-mode sensor design, offering new prospects for environmental monitoring. Full article

Recent advances in electrochemiluminescence (ECL) leveraging thermally activated delayed fluorescence (TADF) have highlighted its potential for near-unity exciton harvesting. However, there are still very limited examples of TADF-ECL emitters. We present a rigid diboron-embedded multiple-resonance TADF emitter, which exhibits blue–green emission at 493 nm with a remarkably narrow bandwidth (FWHM = 22 nm) and minimized singlet-triplet energy gap (ΔE_ST = 0.2 eV), achieving a 67% photoluminescence quantum yield. DFT calculations confirm the short-range charge transfer, enabling narrowband emission. Co-reactant-dependent ECL shows that tripropylamine (TPrA) improves the ECL efficiency from 11% (annihilation) to 51%, while benzoyl peroxide (BPO) yields 1% due to poor radical stabilization. ECL spectra align with photoluminescence, confirming the singlet-state dominance without exciplex interference. TPrA enhances stable radical formation and energy transfer, whereas BPO induces non-radiative losses. These findings establish molecular rigidity and co-reactant selection as pivotal factors in developing high-performance TADF-ECL systems, providing fundamental guidelines for designing organic electrochemiluminescent materials with optimized exciton harvesting efficiency. Full article

Ciprofloxacin (CIP), a widely used broad-spectrum antibiotic, poses a serious threat to human health and environmental safety due to its residues. The complementary monomers molecularly imprinted electrochemiluminescence sensor (MIECLS) based on a polyvinylpyrrolidone-functionalized copper nanowires (CuNWs@PVP) luminescent probe was constructed for the ultra-sensitive detection of CIP. CuNWs with low cost and high conductivity exhibited near-infrared electrochemiluminescence (NIR ECL) properties, yet their self-aggregation and oxidation led to a weakened emission phenomenon. PVP with solvent affinity and large skeleton was in situ attached to CuNWs surface to avoid CuNWs sedimentation and aggregation, and self-enhanced ECL signals were achieved. The bifunctional monomers molecularly imprinted polymer (MIP) possessed complementary active centers that increased their affinity with CIP, enhancing the accurate and sensitive detection of the target substances. The linear range of CIP using MIECLS was 5.00 × 10⁻⁹–5.00 × 10⁻⁵ mol L⁻¹ with a low limit of detection (LOD) of 2.59 × 10⁻⁹ mol L⁻¹, while the recovery rates of CIP in the spiking recovery experiment were 84.39% to 92.48%. The combination of bifunctional monomer MIP and NIR copper-based nano-luminescent probe provides a new method for the detection of CIP in food. Full article

Homogeneous aptasensors that eliminate the need for probe labeling or immobilization hold significant potential for the rapid detection of tumor biomarkers. Herein, a homogeneous aptasensor with electrochemical (EC) and electrochemiluminescence (ECL) dual detection channels was developed by integrating nanochannel-based probe enrichment and DNase I cleavage for selective detection of the tumor biomarker, carbohydrate antigen 125 (CA125). A two-dimensional (2D) composite probe was prepared by assembling the CA125-specific aptamer and the cationic probe tris(2,2′-bipyridyl)Ru(II) (Ru(bpy)₃²⁺), which exhibited both EC and ECL properties, onto graphene oxide (GO) nanosheets (Ru(bpy)₃²⁺/Apt@GO). A vertically ordered mesoporous silica film (VMSF) with ultrasmall, uniform, and vertically aligned nanochannel arrays was rapidly grown on the inexpensive and disposable indium tin oxide (ITO) electrode, forming the detection interface. Due to the size exclusion effect of the ultrasmall nanochannels in VMSF, the Ru(bpy)₃²⁺/Apt@GO probe was unable to penetrate the nanochannels, resulting in no detectable Ru(bpy)₃²⁺ signal on the electrode. Upon specific recognition of CA125 by the aptamer, an aptamer-CA125 complex was formed and subsequently detached from GO. DNase I then cleaved the aptamer-CA125 complex, releasing CA125 and allowing Ru(bpy)₃²⁺ to dissociate into the solution. This enzymatic cleavage enabled CA125 to re-enter the binding cycle, amplifying the release of Ru(bpy)₃²⁺ into the solution. The electrostatic adsorption of the cationic Ru(bpy)₃²⁺ by VMSF significantly enhanced both the EC and ECL signals. The constructed aptasensor exhibited a linear EC detection range for CA125 from 0.1 U/mL to 100 ng/mL, with a limit of detection (LOD) of 91 mU/mL. For ECL detection, CA125 was detected over a range from 0.001 to 100 U/mL, with a LOD as low as 0.4 mU/mL. The developed aptasensor demonstrated excellent selectivity and was successfully applied to the dual-mode EC/ECL detection of CA125 in fetal bovine serum samples. Full article

Rapid, effective, and cost-effective methods for large-scale screening of pesticide residues in the environment and agricultural products are important for assessing potential environmental risks and safeguarding human health. Here, we constructed a novel aggregation-induced emission (AIE) electrochemical aptamer (Apt) sensor based on red-emissive sulfur quantum dots (SQDs), which aimed at the rapid screening and quantitative detection of malathion. SQDs were prepared using a two-step oxidation method with good electrochemiluminescence (ECL) optical properties. These SQDs were modified onto the electrode surface to serve as ECL luminophores. Subsequently, Apt was introduced and modified to form a double-helix structure with the complementary chain (cDNA). The ECL signal was reduced because the biomolecules had poor electrical conductivity and inefficient electron transfer. When the target malathion was added, the double helix structure was unraveled, the malathion Apt fell off the electrode surface, and the ECL signal was restored. The linear range of detection was 1.0 × 10⁻¹³–1.0 × 10⁻⁸ mol·L⁻¹, and the detection limit was 0.219 fM. The successful preparation of the sensor not only develops the ECL optical properties of SQDs but also expands the application of SQDs in ECL sensing. Full article

The sensitive detection of inflammatory biomarkers in gingival crevicular fluid (GCF) is highly desirable for the evaluation of periodontal disease. Luminol-based electrochemiluminescence (ECL) immunosensors offer a promising approach for the fast and convenient detection of biomarkers. However, luminol’s low ECL efficiency under neutral conditions remains a challenge. This study developed an immunosensor by engineering an immunorecognition interface on the outer surface of mesoporous silica nanochannel film (SNF) and confining a Co₃O₄ nanocatalyst within the SNF nanochannels to improve the luminol ECL efficiency. The SNF was grown on an indium tin oxide (ITO) electrode using the simple Stöber solution growth method. A Co₃O₄ nanocatalyst was successfully confined within the SNF nanochannels through in situ electrodeposition, confirmed by X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The confined Co₃O₄ demonstrated excellent electrocatalytic activity, effectively enhancing luminol and H₂O₂ oxidation and boosting the ECL signal under neutral conditions. Using interleukin-6 (IL-6) as a proof-of-concept demonstration, the epoxy functionalization of the SNF outer surface enabled the covalent immobilization of capture antibodies, forming a specific immunorecognition interface. IL-6 binding induced immunocomplex formation, which reduced the ECL signal and allowed for quantitative detection. The immunosensor showed a linear detection range for IL-6 from 1 fg mL⁻¹ to 10 ng mL⁻¹, with a limit of detection (LOD) of 0.64 fg mL⁻¹. It also demonstrated good selectivity and anti-interference capabilities, enabling the successful detection of IL-6 in artificial GCF samples. Full article

Herein, a sensitive electrochemiluminescence (ECL) immunosensor is designed by immobilizing ruthenium-tagged immune complexes at flexible poly-ethylene-glycol (PEG) chains on the electrode surface, which offers more freedom for the collision of the ruthenium complex at the electrode during the initial ECL reaction. The electrochemical characterizations confirm the loose structure of the assembled layer with the immune complex, providing an increase in the current and the resultant enhanced ECL emissions. Comparing the sensors with the rigid structure, a 34-fold increase in the maximal ECL emission is recorded when PEG3400 is used as a linker. Using the optimized protocol, the prepared immunosensor exhibits a wide-ranging linear response to the model antibody (glutamate decarboxylase antibody) ranging from 10 pg/mL to 10 ng/mL. The detection limit is almost two orders lower than the value using the classic enzyme-linked immunosorbent assay, which offers a new design to enhance ECL emissions and the resultant analytical performance. Full article

Dopamine (DA) is an important catecholamine neurotransmitter and its abnormal concentration is closely related to diseases such as hypertension, Parkinson’s disease and schizophrenia. Due to the advantages of high sensitivity and fast response for electrochemiluminescence (ECL), developing ECL sensors for detecting DA was very critical in clinical diagnosis. ECL resonance energy transfer (ECL-RET) was an effective signaling mechanism. However, the shortage of highly efficient ECL-RET pairs impeded the development of DA sensors. Herein, methyl-modified perylene diimide derivative (PDI-CH₃) self-assembly nanorod materials as luminophores and CuO nanomaterials as acceptors were integrated into nanocomposites. An obvious ECL-RET was found in PDI-CH₃/CuO nanocomposites. After PDI-CH₃/CuO nanocomposites were treated with DA, a large increase in ECL intensity was observed. Then, PDI-CH₃/CuO nanocomposites were taken as an ECL platform to detect DA. This ECL sensor exhibited a linear response to DA from 10⁻¹² M to 10⁻⁸ M with a limit of detection of 0.20 pM. Compared with other sensors for DA detection, the constructed ECL sensor exhibited higher sensitivity. In addition, the novel ECL sensor in this work showed good practicability in a human serum sample. Full article

Oseltamivir is a drug that has been widely used to prevent and treat influenza A and B. In this work, an ultrasensitive, simple, and novel electrochemiluminescence (ECL) sensor combined with molecularly imprinted polymers (MIP-ECL) based on a graphene-like two-dimensional material, Mxene quantum dots (MQDs) was constructed to selectively detect oseltamivir. A molecularly imprinted polymer membrane containing an oseltamivir template was constructed by electropolymerization and elution of modified MQDs on a glassy carbon electrode. Under optimized experimental conditions, the MIP-ECL sensor could detect oseltamivir in the range of 10⁻¹⁰ to 10⁻⁶ M (R² = 0.9816), with a low limit of detection of 6.5 × 10⁻¹¹ M (S/N = 3), and the recovery rates of oseltamivir in biological samples were 92.21–104.2%, with relative standard deviations of 3.70%~5.70%. The developed MIP-ECL sensor provides a new idea for detecting oseltamivir, which was successfully applied to the determination of oseltamivir in serum samples, indicating great potential for application in clinical diagnostics. Full article

In this study, we have proposed an electrochemiluminescence (ECL) signal amplification system which is based on two-dimensional (2D) flower-like CdS@Co/Mo-MOF composites as a co-reaction accelerator of the g-C₃N₄/S₂O₈²⁻ system for ultrasensitive detection of chlorpromazine hydrochloride (CPH). Specifically, the 2D flower-like Co/Mo-MOF with mesoporous alleviated the aggregation of CdS NPs while simultaneously fostering reactant-active site contact and improving the reactant–product transport rate. This allowed the material to act as a novel co-reaction accelerator, speeding up the transformation of the S₂O₈²⁻ into SO₄^•− and enhancing the cathodic ECL emission of g-C₃N₄. Moreover, the signal probe which was synthesized by coupling the 2D CdS@Co/Mo-MOF and graphitic carbon nitride (g-C₃N₄) achieved the generation of SO₄^•− in situ and reduced energy loss. The results confirmed that the ECL signal was enhanced 6.2-fold and stabilized by CdS@Co/Mo-MOF. Based on the extremely strong quenching effect of chlorpromazine hydrochloride (CPH) on this system, a “signal-off” type sensor was constructed. The sensor demonstrated excellent sensitivity and linear response to CPH concentrations ranging from 1 pmol L⁻¹ to 100 μmol L⁻¹, with a low detection limit of 0.4 pmol L⁻¹ (S/N = 3). Full article

The measurement of cardiac troponin I (cTnI) is of vital importance for the early diagnosis of acute myocardial infarction. In this study, an enhanced electrochemiluminescent immunoassay for the highly sensitive and precise determination of cTnI was reported. A biomimetic chip with nepenthes peristome surface microstructures to achieve single-layer microbead arrays and integrated microelectrode arrays (MEAs) for ECL detection was microfabricated. Ru@SiO₂ nanoparticles were prepared as signal amplificators labeling immunomagnetic beads. Dendrimer-encapsulated platinum nanoparticles (Pt DENs) were electrochemically modified on ITO MEAs. The resulting Pt DEN-modified ITO MEAs preserved good optical transparency and exhibited an approximately 20-fold ECL signal amplification compared to that obtained from bare ITO. The method made full use of the biomimetic chip with Pt DENs to develop single-layer immunomagnetic bead arrays with increasingly catalyzed electrochemical oxidation of the [Ru(bpy)₃]²⁺–TPA system. Consequently, a limit of detection calculated as 0.38 pg/mL (S/N = 3) was obtained with excellent selectivity, demonstrating significant potential for the detection of cTnI in clinical diagnostics. Full article