Optimal Experimental Conditions Research Articles

Preparation of molecularly imprinted electrochemical sensors for selective detection of hydroxyl radicals based on reduced graphene oxide nanosilver (rGO/AgNPs) composites

An electrochemical sensor for selective detection of hydroxyl radicals (OH) has been developed, which is based on silver nanoparticles and reduced graphene oxide composites (rGO/AgNPs) synthesized in situ by the green reduction method, combined with the electrochemical polymerization method for preparation of molecularly imprinted polymers (MIPs) to modify the screen-printed electrodes. During the assay, the concentration of hydroxyl radicals was obtained by capturing the product 2,5-dihydroxybenzoic acid (2,5-DHBA). Under the optimal experimental conditions, the oxidation peak currents of the target 2,5-DHBA by differential pulse voltammetry (DPV) and its concentration showed a good linear relationship in the concentration ranges of 0.1 ∼ 0.5 μM and 1 ∼ 100 μM, with the limit of detection (LOD) of 0.021 μM. Interference experiments and other studies were also carried out, and the results showed that the sensor has good reproducibility, stability, and selectivity, and the comparison of the detection results with the conventional detection method, high-performance liquid chromatography, indicated the accuracy of the sensor detection, which is a convenient, sensitive, and efficient method for the detection of hydroxyl radicals.

Highly efficient capacitive deionization of copper(Ⅱ) ions from wastewater in symmetric Ti3C2Tx MXene-based electrode: Performance, optimization and deionization mechanism

Due to the use of Cu(II) ions as catalysts, the production of polyacrylamide generates Cu-containing wastewater, constituting an environmental safety hazard and a waste of resources. This study proposes symmetric Ti3C2Tx MXene-based electrodes for capacitive deionization to remove Cu(II) ions from chemical wastewater as a clean, low-energy, and resource-recyclable method and investigates their performances and mechanisms. Results showed that the adsorption capacity and removal efficiency of Cu(II) ions could reach 49.4 mg·g−1 and 98.6% under the optimal experimental conditions (the initial Cu(II) ions concentration was 100.0 mg·L−1, imposed voltage of 1.0 V, circulation velocity of 25.0 mL·min−1, and the initial pH of 4.0). At the same time, the adsorption capacity and removal efficiency of Cu(II) ions in real copper-containing wastewater were 47.4 mg·g−1 and 97.7%. In addition, by analyzing the changes of the electrode, the mechanism of electroadsorption was determined to include capacitive electroadsorption (double layer with pseudo-capacitance synergy) and cathodic electrodeposition. Ultimately, by applying a reverse voltage, Ti3C2Tx MXene-based electrodes can be rapidly regenerated and recycled for continued use as catalysts. This simple operation has the advantage of potential economic benefits. Therefore, the Ti3C2Tx MXene-based electrodes can be used potentially to remove Cu(II) ions in practical applications for environmental remediation.

Research on differential pulse voltammetry detection method for low concentration glucose based on machine learning model

In the electrochemical detection process, determining the optimal experimental conditions for the standard curve often requires multiple iterations. A low-concentration glucose detection method that combines electrochemical principles with machine learning was introduced to address the challenge of determining the optimal reactant addition in electrochemical detection. We developed a model that incorporates electrochemical curve features and various experimental conditions as variables. Concentration regression analysis was conducted using five machine learning models: Multiple Linear Regression (MLR), Decision Trees (DT),Artificial Neural Networks (ANN), Random Forest (RF), and Extreme Gradient Boosting (XGBoost). The results show that the performance of the XGBoost model surpasses that of the other models. Compared to the second place—Random Forest model, it reduces the Mean Absolute Error (MAE) by 21.6 % and the Root Mean Square Error (RMSE) by 25.3 %. This method can be used for low-concentration glucose detection, addressing the challenge of determining the optimal experimental conditions. It mitigates the impact of experimental conditions on detection results, enhances concentration determination accuracy, and provides new methods for determining the optimal experimental conditions and improving detection accuracy in the field of detection and analysis.

Development of a dispersive liquid–liquid microextraction procedure based on a natural deep eutectic solvent for ligand-less preconcentration and determination of heavy metals from water and food samples

In the current study, a ligand-less dispersive liquid–liquid microextraction technique assisted ultrasound and vortex equipment (DLLME-A-US-V) procedure was used for the simultaneous preconcentration and extraction of heavy metal ions. The proposed method was done by a natural hydrophobic deep eutectic solvent for the extraction of arsenic, cadmium, lead, and mercury ions without a complexing agent. The natural deep eutectic solvent was prepared from l-menthol (M) and salicylic acid (SA). The precursor of deep eutectic solvents strongly affects the extraction of metal ions. Among the studied solvents, hydrophobic deep eutectic solvents showed the highest extraction recovery. Under optimal experimental conditions, the method linearity, limits of detection (LOD), limits of quantification (LOQ), relative standard deviations (RSD %), enrichment factors (EF), and extraction recovery (% ER) were equal to 0.005–14 µg/L, 0.0043–0.0088 µg/L, 0.0143–0.0294 µg/L, 1.66–2.83 %, 112–120, and 90–96 %, respectively. The obtained coefficients of determination (r2) were also higher than 0.991. This method was successfully applied to determine some heavy metals in food samples in the ultra-trace range with the recovery values of real samples being 93–108 %.

Electrochemical sensing of bisphenol A based on carboxylated multiwalled carbon nanotubes-ferrocene-H5PMo10V2O40 with chitosan for signal amplification

A synergetic signal amplification detection platform based on carboxylated multiwalled carbon nanotubes-ferrocene-H5PMo10V2O40 (CMWNT-Fc-PMo10V2) composite is initially developed to detect bisphenol A (BPA). The CMWNT-Fc-PMo10V2 composite has been synthesized by the interaction of Fc and PMo10V2 with CMWNT as the loading support. Furthermore, the CMWNT-Fc-PMo10V2 composite with negative charge could be firmly immobilized on the cationic chitosan (CHIT) matrix with film-forming ability through the electrostatic attraction, which could overcome the problems that Fc and PMo10V2 could not be stably fixed on the electrode surface. Benefiting from the large surface area and good conductivity of CMWNT, fast electron-transfer rate and low oxidation potential of Fc, and strong redox property of PMo10V2, CMWNT-Fc-PMo10V2-based sensor demonstrates synergistic effect in electrochemical detection of BPA. Under the optimal experimental conditions, the wide linear range from 0.06 to 100 μM, and low detection limit of 0.035 μM for BPA was achieved at the CMWNT-Fc-PMo10V2 sensing interface. Moreover, the newly developed electrochemical method was successfully used for determination of BPA in milk samples with satisfactory results.

Carboxyl-functionalized magnetic amide-linked covalent organic framework for efficient extraction of multi-class mycotoxins from soybeans prior to HPLC-MS/MS analysis

Mycotoxins co-contamination in soybean poses great risks to human health, however, due to their diverse structures, it is difficult to simultaneously extract and detect these multi-mycotoxins. By incorporating modification of hydrophilic carboxyl groups with the hydrophobic properties of covalent organic frameworks, a stable cubic carboxyl-functionalized magnetic amide-linked covalent organic framework were fabricated, characterized and utilized as adsorbents for magnetic solid phase extraction (MSPE) of eleven frequently detected mycotoxins from soybeans followed by HPLC-MS/MS analysis. The key MSPE parameters were screened using the Plackett-Burman design and optimized with the Box-Behnken design for response surface methodologies. Under the optimal experimental conditions, the linear range was 0.2–50 μg/kg, the limits of detection were 0.1–1.4 μg/kg. The established method was applied for the soybean analysis with satisfactory recoveries (70.8–108.3%) and precision (intra- and inter-relative standard deviations of 2.1–9.2% and 1.6–11.1%, respectively). With proper modification, this method may have great application potential for simultaneously analyzing and monitoring the multi-mycotoxin contamination in foods to ensure consumer safety and public health.

CO2‐NBs‐ assisted enzymatic hydrolysis as a new green approach for extraction of phenolic compounds from rhizomes of Polygonatum cyrtonema Hua

SummaryThe integration of carbon dioxide‐nanobubbles (CO2‐NBs) with cellulase has led to the development of an innovative extraction system for phenolic compound retrieval from P. cyrtonema (Polygonatum cyrtonema) Hua rhizomes. Four critical factors influencing on CO2‐NBs‐cellulase were methodically investigated and optimised through single‐factor experiments. The optimal experimental conditions are 30 cycles, 0.35 MPa, pH 5.45 and 0.025 g/mL cellulase aqueous solution. The stability of system was characterised meticulously, indicating the viability for at least 24 h. Comparative assessment of bioactive constituents and antioxidant activity demonstrated exceptional extraction efficiency and potential synergistic effects of CO2‐NBs‐cellulase. Synergistic effects and reaction mechanisms during extraction were explored using Fourier‐transform infrared spectroscopy, differential scanning calorimetry and scanning electron microscopy, which contributed to mechanism understanding with significant alterations in partial structure and heightened thermal stability we found. In essence, this study introduces an eco‐friendly, energy‐efficient extraction system paradigm based on a novel nanobubble‐enzyme binding approach.

Priority recovering of lithium from spent lithium-ion battery cathode powder by pyrolysis reduction of Bidenspilosa

In this paper, the invasive plant Bidens pilosa was used as a carbon material to roast and reduce the cathode powder of spent ternary lithium-ion batteries (LiNixCoyMn1-x-yO2), to alleviate lithium resource scarcity and the problems of large spent of batteries which is harmful to the environment. The transition metals in the cathode powder were reduced to Ni, Co, and MnO, respectively, and the Li element in the cathode powder was reacted to generate Li2CO3. The experiment explored the reduction effect of high valent metals in spent lithium-ion batteries at different roasting temperatures and biomass ratios, and the impact of different time on the leaching of Li element. Results showed that the optimal experimental conditions of reduction roasting were as follows: temperature 700 °C, biomass ratio 20%. The leaching efficiency of Li obtained under optimal roasting conditions through leaching was 94.15%. TG-DSC/MS, XRD, XPS, SEM, and other instruments characterized the experimental results. This method not only efficiently converts Bidens pilosa into a carbon-reducing agent and solves the problem of plant invasion, but also promotes the decomposition of spent cathode powder, reduces high valence metals to single metals and low valence oxides, and generates Li2CO3 through reaction, which can selectively extract lithium element and reduce the amount of reagent added and the use of reducing agent in the subsequent leaching process.

Fe3O4-CdO Nanocomposite for Organic Dye Photocatalytic Degradation: Synthesis and Characterization

In this study, pure CdO nanoparticles, magnetic Fe3O4 nanoparticles, and Fe3O4-CdO nanocomposites were prepared via a solution combustion method using cetyltrimethylammonium bromide (CTAB) as a template. These prepared nanomaterial samples were characterized by X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron microscopy (XPS), transmittance electron microscopy (TEM), and scanning electron microscopy (SEM) analysis. XRD patterns confirmed the purity and the crystalline nature of the prepared samples. FTIR and Raman spectra observed the metal-oxygen (M-O) bond formation. UV-vis DRS studies were performed to investigate the optical properties and the bandgap energy determination. The surface morphology and the size of the pure CdO nanoparticles, magnetic Fe3O4, and nanocomposites of Fe3O4-CdO were determined via TEM and SEM analysis. Under optimum experimental conditions, the Fe3O4-CdO nanocomposites were applied for photocatalytic activity against Methylene blue dye. Under visible light irradiation, Fe3O4-CdO nanostructures showed an efficient photocatalytic degradation of 92% against Methylene blue organic dye and showed excellent stability for multiple cycles of reuse.

Probing aptamer-mucin 1 binding events on polydopamine@carbon nanotubes modified cellulose paper interface using speckle pattern analysis for label free aptasensing

Herein, we have developed a cellulose paper-based aptasensing protocol by employing dynamic laser speckle (DLS) analysis for direct and label-free probing of the binding interface. Cellulose filter paper surface was modified by using the mussel adhesion chemistry of polydopamine modified carbon nanotubes (PDA@CNTS). The mussel chemistry resulted in strong adhesion and binding of PDA@CNTs on cellulose paper surface. The modified surface was subsequently employed in the construction of label free aptasensor for detection of cancer biomarker mucin 1 (MUC1). Taking advantage of DLS technique, it provided us with sensitive and accurate analysis of target biomarker MUC1 by the intrinsic randomness of patterns generated from cellulose based paper surface. The developed aptasensor was evaluated using DLS at various fabrication steps, where the scattered laser beams from these samples were collected and analyzed based on the obtained speckle patterns. Under the optimal experimental conditions, paper-based aptasensor achieved sensitive and selective detection of MUC1, exhibiting excellent linear range (15–100) µM with a limit of detection of 1 µM. This work presents a novel study of promising laser speckle paper-based aptasensor, providing new insights for the development of low-cost, sensitive, and portable paper-based analytical tools for biological applications.

Copolymers functionalized with quaternary ammonium compounds under template chain exhibit simultaneously efficient bactericidal and flocculation properties: Characterization, performance and mechanism

In this work, novel multifunctional cationic template copolymers with flocculation and sterilization capabilities were synthesized using a low-pressure ultraviolet (LP-UV) template polymerization method for the removal of kaolin and Escherichia coli (E. coli) from water. The influence of template agents on the structural performance of the copolymers was evaluated through characterization, which showed that template copolymer TPADM possesses a higher cationic charge density and a more complex rough surface, contributing to better flocculation performance than that of the non-template copolymer CPADM. Under optimal experimental conditions, TPADM-1 exhibited removal rates of 98.45% for kaolin and 99% for E. coli (OD600 =0.04), marginally outperforming the non-template copolymer. Simultaneously, TPADM-1 produced good adaptability to kaolin and E. coli wastewater in terms of wide pH, speculating that charge neutralization, adsorption bridging, patching, and sweeping simultaneously dominate the flocculation mechanism. Interestingly, SEM and 3D-EEM analysis confirm that the sterilization of E. coli occurs through two distinct functions: initially adsorption followed by subsequent cell membrane rupture and leakage of cellular contents, ultimately leading to cell death. This research further confirms the feasibility of the designed novel multifunctional copolymers for achieving simultaneous disinfection and turbidity removal, demonstrating practical applicability in real water treatment processes.

Cyclic Multiple Primer Generation Rolling Circle Amplification Assisted Capillary Electrophoresis for Simultaneous and Ultrasensitive Detection of Multiple Pathogenic Bacteria.

Efficient, accurate, and economical detection of pathogenic bacteria is crucial in ensuring food safety and preventing foodborne illnesses. How to fulfill the highly sensitive and simultaneous detection of multiple trace pathogenic bacteria is a big challenge. In this work, capillary electrophoresis coupled with a cyclic multiple primer generation rolling circle amplification (cyclic MPG-RCA) was studied for highly sensitive and simultaneous detection of three kinds of pathogenic bacteria. The cyclic MPG-RCA was based on a carefully designed clover-shaped DNA probe, in which three "leaves" corresponded to three types of aimed pathogenic bacteria: Shigella dysenteriae (S. dysenteriae), Salmonella enterica subsp. enterica serovar Typhi (S. Typhi), and Vibrio parahaemolyticus (V. parahaemolyticus). Under the optimal experimental conditions, the limits of detection (S/N = 3) of this method for bacterial target DNA were 11.4 amol·L-1 (S. dysenteriae), 4.88 amol·L-1 (S. Typhi), and 14.9 amol·L-1 (V. parahaemolyticus), and the conversion concentrations for the target bacteria were 10 colony-forming units (CFU)·mL-1 (S. dysenteriae), 3 CFU·mL-1 (S. Typhi), and 12 CFU·mL-1 (V. parahaemolyticus). This method had been applied to the detection of tap water samples with good results, which proved that it could be used as an effective tool for trace pathogenic bacteria monitoring in foods, environments, and medicines.

One-pot, room-temperature synthesis of novel Ag2WO4/AgVO3 composites with high photocatalytic activities under visible light irradiation

BackgroundEnergy shortages and environmental pollution are two of the most immediate problems all over the world. Photocatalysis is expanding into energy and environmental applications. MethodsIn this study, novel visible-light-driven Ag2WO4/AgVO3 composite photocatalysts were constructed via a one-pot, controllable, ligand-free and eco-friendly approach and analyzed using different techniques. Under visible light irradiation, photocatalytic behavior of type-II heterojunctions in the degradation of levofloxacin hydrochloride is investigated. Significant findingsVarious characterizations showed that Ag2WO4 was successfully loaded onto the AgVO3 surface, which improved the separation and transfer efficiency of the photogenerated charge carriers. Under optimal experimental conditions, the removal efficiency of levofloxacin reached 0.0194 min-1 for the Ag2WO4/AgVO3 composites with a 3 : 5 mass ratio (3-WV), which was 5.87 and 17.64 times that of pure AgVO3 and Ag2WO4, respectively. The photocatalytic mechanism of typical type-II heterojunction was discussed. Furthermore, possible photodegradation pathway of levofloxacin was comprehensively determined by LC-MS analysis. This work will provide new motivation for the design and synthesis of simple preparation and highly efficient photocatalysts for environmental purification.

Transesterification of acidic palm oil using solid waste/CaO as a bifunctional catalyst

Conventional solid base catalysts are difficult to adapt to the low-grade oil used in the industrial production of biodiesel due to the high acidity. In this paper, an acid-base bifunctional catalyst loaded with CaO from the solid waste of blast furnace dust was prepared to produce biodiesel by transesterification. Meanwhile, palm oil with oleic acid was used to simulate acid oil. The catalysts were characterized by XRD, XPS, BET, SEM-EDX, CO2-TPD and NH3-TPD. The biodiesel produced was tested and found to be compliant with ASTM D 6751. the response surface method based on the Central composite design (RSM-CCD) is used to optimize key parameters for the production of biodiesel. Under the optimal experimental conditions (i.e., methanol to oil ratio of 15.24, catalyst dosage of 7.96%, reaction temperature of 148.95 °C and reaction duration of 2 h, even with the oleic acid addition of 4%) the yield of biodiesel prepared by SW-CaO catalyst was 87.67%.

Activated carbon from sugarcane bagasse as support for lipase immobilization by physical adsorption technique

Lipases are recognized as the most important group of catalysts in biotechnology. However, utilization of free enzymes is often hampered by the need for more operational stability, high cost, and non-reusability. Most of these obstacles can be solved by lipase immobilization. This work's objective was to evaluate the performance of the activated carbon obtained from sugarcane straw (SAC) as a support for lipase immobilization. Two lipases were immobilized by physical adsorption on SAC: Aspergillus niger 11T53A14 lipase and CalB (lipase B from Candida antarctica, Novozymes). Results revealed that the lipase had been anchored on the activated carbon with the lipase binding efficiency of 89 % (A. niger lipase) and 100 % (CalB) at the optimum experimental conditions (initial protein concentration 0.1 mg mL-1, 0.15 g of SAC, 25 °C, and 120 min). Langmuir isotherm fitted the adsorption equilibrium data of the lipases on SAC. SAC presents a high surface area and protein adsorption capacity. These results show that activated carbon synthesized from the sugarcane straw is a promising support for enzyme immobilization.

Efficient activation of peroxymonosulfate with zirconia-supported manganese and cobalt catalysts for oxidation of ibuprofen

This study assessed the efficacy of ZrO2-based catalysts with different Mn(II) and Co(II) metal loadings for catalytic degradation of ibuprofen using peroxymonosulfate anion as oxidant. The support was prepared via co-precipitation, and metal ion deposition was achieved through incipient wetness impregnation. Catalysts were characterized by atomic absorption spectrometry, X-ray diffraction, Fourier-Transform infrared spectroscopy, and scanning electronic microscopy. Optimal experimental conditions resulted in complete ibuprofen degradation in 30 min, with 63.3% mineralization. The best-performing catalyst was reusable up to three times. Both sulfate and hydroxyl radicals were generated in the oxidant activation process.

Defluorination of perfluorooctanoic acid and perfluorooctane sulfonic acid by heterogeneous catalytic system of Fe-Al2O3/O3: Synergistic oxidation effects and defluorination mechanism

In this study, catalytic ozonation by Fe-Al2O3 was used to investigate the defluorination of PFOA and PFOS, assessing the effects of different experimental conditions on the defluorination efficiency of the system. The oxidation mechanism of the Fe-Al2O3/O3 system and the specific degradation and defluorination mechanisms for PFOA and PFOS were determined. Results showed that compared to the single O3 system, the defluorination rates of PFOA and PFOS increased by 2.32- and 5.92-fold using the Fe-Al2O3/O3 system under optimal experimental conditions. Mechanistic analysis indicated that in Fe-Al2O3, the variable valence iron (Fe) and functional groups containing C and O served as important reaction sites during the catalytic process. The co-existence of 1O2, OH, O2− and high-valence Fe(IV) constituted a synergistic oxidation system consisting of free radicals and non-radicals, promoting the degradation and defluorination of PFOA and PFOS. DFT theoretical calculations and the analysis of intermediate degradation products suggested that the degradation pathways of PFOA and PFOS involved Kolbe decarboxylation, desulfonation, alcoholization and intramolecular cyclization reactions. The degradation and defluorination pathways of PFOA and PFOS consisted of the stepwise removal of -CF2-, with PFOS exhibiting a higher defluorination rate than PFOA due to its susceptibility to electrophilic attack. This study provides a theoretical basis for the development of heterogeneous catalytic ozonation systems for PFOA and PFOS treatment.

Nanogold-decorated reduced graphene oxide/chitosan composite for electrochemical sensing of N-acetyl-4-aminophenol

In this study, a novel electrocatalyst designed by doping gold nanoparticles (AuNPs) over the reduced graphene oxide (rGO)/Chitosan (CTSN) matrix for the determination of N-acetyl-4-aminophenol, i.e. acetaminophen (AC) in phosphate buffer solution has been reported. The catalyst was synthesized via a simple ultra-sonication process followed by a photo-reduction technique to obtain 1%AuNPs@5%rGO/CTSN nanocomposite. The conductivity of the CTSN biopolymer was enhanced by coupling rGO and thereafter rGO/CTSN surface was decorated with nano-Au particles to improve the catalytic efficiency. The structural and surface properties of the as-fabricated nanocomposite have been thoroughly investigated using cutting–edge microscopic and spectroscopic techniques. The catalytic and sensing phenomena were systematically studied with several well-known electrochemical techniques. Using differential pulse voltammetry (DPV), the peak current was found to be linear across the AC concentration range of 0.50 μM–39.31 μM, with a high sensitivity of 2.358 μAμM−1cm−2 and a low limit of detection (LOD) of 0.06 μM. Moreover, under optimal experimental conditions, the amperometric (i-t) study showed a high sensitivity value of 0.935 μA μM−1cm−2, a wide AC detection range (5.0 μM–160 μM), and LOD 0.151 μM. The proposed sensor also demonstrated high selectivity in the existence of common interfering species. In addition, this newly fabricated sensor electrode exhibited admirable reproducibility, repeatability, and remarkable storage and operational stability. It was also successfully applied to AC recovery tests in real samples as a pharmaceutical formulation.

MXene/Cellulose Hydrogel Composites: Preparation and Adsorption Properties of Pb2.

In this work, acrylic cellulose hydrogel, a typical natural polymer adsorbent, was modified using MXene through in situ polymerization to create a synthetic inorganic-polymer composite known as MXene/cellulose hydrogel. FTIR, XRD, SEM, and thermogravimetric analyses were applied to characterize the chemical structure and micromorphology. The MXene/cellulose hydrogel was utilized for the removal of Pb2+ from wastewater. Under optimal experimental conditions (initial Pb2+ concentration of 0.04 mol/L, adsorption time of 150 min, pH = 5.5, and MXene doping content of 50% at 30 °C), a maximum adsorption capacity of 410.57 mg/g was achieved. The MXene/cellulose hydrogel corresponded with the pseudo-second-order kinetic equation model and exhibited a better fit with the Freundlich isotherm model.

Sensitive electrochemiluminescence immunosensor based on a novel luminescent europium metal–organic framework and antenna effect for detecting pro-gastrin-releasing peptide

Sensitive detection of pro-gastrin-releasing peptide (Pro-GRP) is crucial because it is a highly sensitive and specific tumor marker for small cell lung cancer. Herein, we synthesized an efficient luminescent europium metal–organic framework and developed a sandwich ECL immunosensor for the sensitive detection of Pro-GRP, which used Eu3+ as the central ion and 2,4,6-tri (4-carboxyphenyl)-1,3,5-triazine (H3TATB) as the organic ligand. H3TATB acted as a strong absorbing reagent and transferred its energy to Eu3+ via the antenna effect to enhance the ECL response signal of Eu3+. As per calculations, the ECL efficiency of Eu-TATB, which was a promising ECL luminophore, was up to 130 %. The Cu2O cube worked as a substrate to assist the electron transfer and was used as a co-reaction accelerator to catalyze S2O82− to produce more SO4•− and then enhance the ECL intensity of Eu-TATB. Under optimal experimental conditions, the ECL immunosensor had a linear range of 5 fg mL−1–50 ng mL−1 for detecting Pro-GRP with a detection limit of 1.6 fg mL−1; moreover, it demonstrated excellent stability and specificity and has been successfully applied for detecting Pro-GRP in the human serum.