Electrochemiluminescence of an iridium complex doped with SiO2 nanoparticles to detect 2-adamantanamine based on the host-guest interaction of cucurbit[7]uril.

The poor solubility of iridium complexes severely hampers its application in the electrochemiluminescence (ECL) sensing field. The doping of an iridium complex with silica (SiO2) nanospheres provides feasible solution for this problem. Herein, one kind of water insoluble iridium complex ([Ir(dFppy)2(d(CF3)bpy)](PF6)) was doped with SiO2 nanoparticles to obtain a luminescent nanocomposite (SiO2@Ir) which could generate strong ECL signals to act as a beacon molecule. An "off-on-off" mode ECL sensor was proposed based on the competitive host-guest interactions between 2-adamantanamine (2-ADA), ferrocene (Fc) and cucurbit[7]uril (Q[7]). Fc could be used as an inhibitor to decrease the ECL signal, while Q[7] could wrap Fc to recover the ECL signal. Q[7] has a stronger binding ability with 2-ADA than Fc. As a result, 2-ADA could replace Fc from the cavity of Q[7], and the ECL signal was inhibited again. Under the optimal conditions, the ECL intensity varied linearly with 2-ADA concentration in the range of 1.0 × 10-8 to 1.0 × 10-6 mol L-1 with a detection limit of 2.5 × 10-10 mol L-1. The results not only provided a new avenue for the application of water insoluble iridium complexes in ECL sensing, but also revealed the attractive potential of host-guest interactions in the fabrication of biosensors.

Sensitive detection of uric acid based on low-triggering-potential cathodic luminol electrochemiluminescence achieved by ReS2 nanosheets.

The majority of previously reported cathodic electrochemiluminescence (ECL) systems often required very negative potential to be carried out, which has greatly limited their applications in the sensing field. Screening high-performance cathodic ECL systems with low triggering potential is a promising way to broaden their applications. In this work, rhenium disulfide nanosheets (ReS2 NS) have been revealed as an efficient co-promoter to realize low-triggering-potential cathodic luminol ECL. One strong cathodic ECL signal appeared at a potential of -0.3 V and one anodic ECL peak was obtained at -0.15 V under the reverse potential scan, which were caused by electrogenerated reactive oxygen species (ROS) from hydrogen peroxide. The generation of strong luminol ECL at low potential was the result of the electrocatalytic effect of ReS2 NS on the reduction of H2O2. The scavenging effect of uric acid (UA) on the ROS could significantly inhibit the cathodic ECL. As a result, an ECL sensor was proposed, which showed outstanding performance for the detection of UA in the range of 10 nM to 0.1 mM with a low detection limit of 1.53 nM. Moreover, the ECL sensor was successfully applied in the sensitive detection of UA in real samples. This work provides a new avenue to establish a low-potential cathodic ECL system, which will sufficiently expand the potential application of cathodic ECL in the sensing field.

Promoting effect of TiVC MXene on cathodic electrogenerated chemiluminescence of Ru(bpy)32+ and its application in the sensitive detection of sulfite.

The enhanced cathodic ECL of Ru(bpy)32+ at a bimetallic element MXenes (TiVC MXene) modified electrode in neutral aqueous condition is reported. TiVC MXene significantly catalyzed the oxygen reduction reaction (ORR) as well as the electrochemical reduction of Ru(bpy)32+ to produce reactive oxygen species and Ru(bpy)3+. The obtained hydroxyl radical (OH∙) not only oxidized Ru(bpy)3+ to generate Ru(bpy)32+* and emit light through coreactant pathway, but also oxidized Ru(bpy)32+ to Ru(bpy)33+, which caused an annihilation ECL reaction. As a result, two pathways occurred simultaneously to generate strong cathodic ECL signal. Sulfite removes the dissolved oxygen in water and reduces the occurrence of ORR, which prohibits the generation of OH∙ to decrease the ECL signal. The decrement of ECL intensity varied linearly with the concentration of sulfite in the range 2 nM to 50 µM with a detection limit of 0.14 nM (3σ). The proposed sensor exhibited good analytical performance, and could be used in the detection of sulfite in real samples. The results revealed that the electrocatalytic behavior of TiVC MXene is the key factor for strong cathodic Ru(bpy)32+ ECL, which provides new application in ECL sensing field.

Electrogenerated chemiluminescence resonance energy transfer between luminol and MnO2 nanosheets decorated with Cu2O nanoparticles for sensitive detection of RNase H.

In the present work, a novel approach was developed for the preparation of Cu2O nanoparticle decorated MnO2 nanosheets (Cu2O@MnO2). Uniformly dispersed Cu2O nanocrystals were produced on the surface of MnO2 nanosheets by in situ reduction under refluxing conditions. The unique structure of the used MnO2 nanosheet support played a vital role in the preparation of such Cu2O@MnO2 nanocomposites. The electrogenerated chemiluminescence (ECL) resonance energy transfer can occur between the luminol/H2O2 system and Cu2O@MnO2 nanocomposites, resulting in a decrease of the ECL intensity, which can be used to fabricate an ECL sensor. Cu2O@MnO2 nanocomposite modified heterologous DNA/RNA duplexes were modified on the GCE to construct an ECL-RET system, leading to the decrease of ECL intensity. As a highly conserved damage repair protein, RNase H can specifically hydrolyze RNA in DNA/RNA strands to release Cu2O@MnO2 nanocomposites and recover the ECL signal. As a result, an "off-on" mode ECL sensor for sensitive RNase H assay was fabricated. Under the optimal conditions, the detection limit of RNase H is 0.0005 U mL-1, which is superior to other approaches. The proposed method provides a universal platform for monitoring RNase H, and exhibits great potential in bioanalysis.

Synthesis of Se single atoms on nitrogen-doped carbon as novel electrocatalyst for sensitive nonenzymatic sensing of hydrogen peroxide.

Single-atom catalysts received increasing attention due to their maximum atom utilization efficiency. However, metal-free single atoms have not been used to construct electrochemical sensing interfaces. In this work, we demonstrated the use of Se single atoms (SA) as electrocatalyst for sensitive electrochemical nonenzymatic detection of H2O2. Se SA was synthesized and anchored on nitrogen-doped carbon (Se SA/NC) via a high-temperature reduction strategy. The structural properties of Se SA/NC were characterized by transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electrochemical techniques. The results showed that Se atoms were uniformly distributed on the surface of the NC. The obtained SA catalyst exhibited excellent electrocatalytic activity toward H2O2 reduction, and can be used to detect H2O2 in a wide linear range from 0.04 mM to 11.1 mM with a low detection limit of 0.018 mM and high sensitivity of 403.9 µA mM-1 cm-2. Moreover, the sensor can be used for the quantification of H2O2 concentration in real disinfectant samples. This work is of great significance for expanding the application of nonmetallic single-atom catalysts in the field of electrochemical sensing. Se single atoms (Se SA) as novel electrocatalyst were synthesized and anchored on nitrogen-doped carbon (NC) for sensitive electrochemical nonenzymatic detection of H2O2.

Dual-potential electrochemiluminescence from black phosphorus and graphitic carbon nitrides for label-free enzymatic biosensing.

Simultaneous anodic and cathodic electrochemiluminescence (ECL) emissions of black phosphorus nanosheets (BPNSs) and graphitic carbon nitrides (g-C3N4) were reported based on the co-existence of different co-reactants. Anodic ECL was obtained at the BPNSs modified electrode with tripropylamine (TPrA) as a co-reactant, while g-C3N4 was selected as another emitter to obtain cathodic ECL emission with K2S2O8 as co-reactant. Employing the superiority of two separate ECL systems, a facile ECL method was developed for cholesterol detection based on cholesterol oxidase (ChOx) immobilized g-C3N4/BPNSs modified glassy carbon electrode (g-C3N4/BPNSs/GCE). False positive signals can be significantly reduced based on the separation of anode and cathode ECL signals from BPNSs and g-C3N4, respectively. The proposed biosensor provided a quantitative readout proportional to cholesterol concentrations in the range from 0.5 µM to 0.5 mM with a detection limit of 0.14 µM (cathodic system, 3σ, n = 6) and 0.32 µM (anodic system, 3σ, n = 6). The proposed biosensor demonstrated excellent analytical performance with remarkable sensitivity, manifesting its potential application in enzymatic biosensing field.

An electrogenerated chemiluminescence aptasensor for lysozyme based on the interaction between Ru(bpy)3 2+ and cucurbit[8]uril.

Strong anodic Ru(bpy)3 2+ electrogenerated chemiluminescence (ECL) was obtained at a cucurbil[8]uril (CB[8]) modified electrode in neutral conditions without the need of an additional coreactant. An ECL aptasensor was fabricated based on the strong ECL emission as well as the host-guest interaction between DNA and CB[8]. Firstly, amino group-terminated complementary DNA (DNA-NH2 ) was firmly immobilized on CB[8]/glass carbon electrode, which could further increase ECL intensity. Then, a ferrocene group-terminated lysozyme aptamer (Fc-DNA) was hybridized with complementary DNA. The inhibiting effect of ferrocene on Ru(bpy)3 2+ ECL resulted in the apparent decrease in ECL signal. When the modified electrode was incubated in lysozyme, specific binding between lysozyme and its aptamer could release the ferrocene group from the electrode surface, and the ECL emission was recovered. As a result, an 'on-off-on' mode ECL aptasensor for lysozyme was fabricated. In the range 0.14-140 pg ml-1 , the increased ECL intensities exhibited excellent linearity with the logarithm of lysozyme concentrations, and the detection limit was calculated as 0.093 pg ml-1 (3σ). The proposed ECL aptasensor exhibited satisfactory analytical performance, revealing the potential application of CB[n]s in an ECL sensing field.

Dual-potential electrochemiluminescence of single luminophore for detection of biomarker based on black phosphorus quantum dots as co-reactant.

Simultaneous cathodic and anodic electrochemiluminescence (ECL) emissions of needle-like nanostructures of Ru(bpy)32+ (RuNDs) as the only luminophore are reported based on different co-reactants. Cathodic ECL was attained from RuNDs/K2S2O8 system, while anodic ECL was achieved from RuNDs/black phosphorus quantum dots (BPQDs) system. Ferrocene attached to the hairpin DNA could quench the cathodic and anodic ECL simultaneously. Subsequently, the ECL signals recovered in the presence of tumor marker mucin 1 (MUC1), which made it possible to quantitatively detect MUC1. The variation of ECL signal was related linearly to the concentrations of MUC1 in the range 20 pg mL-1 to 10 ng mL-1, and the detection limits were calculated to 2.5 pg mL-1 (anodic system, 3σ) and 6.2 pg mL-1 (cathodic system, 3σ), respectively. The recoveries were 97.0%, 105%, and 95.2% obtained from three human serum samples, and the relative standard deviation (RSD) is 5.3%. As a proof of concept, this work realized simultaneous ECL emission of  a single luminophore, which initiates a new thought in biomarker ECL detection beyond the traditional ones. Simultaneous cathodic and anodic ECL emissions of RuNDs were reported based on different co-reactants. Ferrocene could quench the ECL emission in the cathode and the anode simultaneously. Thus, an aptasensor was constructed based on the variation of ECL intensity. As a proof of concept, this work realized simultaneous ECL emission of a single luminophore, which initiates a new thought in biomarker ECL detection beyond the traditional ones by avoiding the false positive signals.

Electrogenerated chemiluminescence resonance energy transfer between ZnGa2O4/g-C3N4 and gold nanoparticles/graphene and its application in the detection of thrombin.

In the present work, ZnGa2O4 was incorporated with g-C3N4 nanosheets to synthesize ZnGa2O4/g-C3N4 nanocomposites through the hydrothermal method. The morphologies of nanocomposites were characterized by TEM, XRD, and spectral and electrochemical methods, respectively. The nanocomposites exhibited greatly enhanced fluorescence with the maximum emission peak red-shifted from 380 nm to 450 nm. A strong cathodic electrogenerated chemiluminescence (ECL) signal of ZnGa2O4/g-C3N4 nanocomposites was obtained under neutral conditions, which was much stronger than those of pure materials. ECL resonance energy transfer (ECL-RET) occurred between ZnGa2O4/g-C3N4 and gold nanoparticle/graphene nanocomposites, resulting in an apparent decrease of the ECL signal. Based on this, a label-free ECL sensor for thrombin was fabricated. The sensor showed high sensitivity, wide linearity, and good selectivity for the detection of thrombin in the range from 1.37 fM to 27.4 pM with a detection limit of 0.55 fM (3σ). The proposed method was applied to detect thrombin in serum samples with satisfactory results. This work revealed a new role of spinel-type semiconductor oxide nanomaterials, which will provide more ECL systems for the fabrication of biosensors.

Electrochemiluminescence resonance energy transfer between luminol and black phosphorus nanosheets for the detection of trypsin via the "off-on-off" switch mode.

In this work, the electrochemiluminescence (ECL) behavior of a luminol-H2O2 system was studied on a black phosphorus nanosheet (BPN) modified electrode. A quenching effect of BPNs on luminol ECL was achieved based on ECL resonance energy transfer (ECL-RET) with excited state luminol as the energy donor and BPNs as the energy acceptor. Protamine could bind on the surface of BPNs through electrostatic interactions, which can cut off the energy transfer route between luminol and BPNs to restore the ECL signal. The immobilized protamine could be hydrolyzed by trypsin, as a result, the BPN surface was exposed and RET occurred again, resulting in an instant decrease in the ECL intensity. The reduced ECL signals varied linearly with trypsin concentrations, and could be indirectly used in the sensitive detection of trypsin in the range of 100 ng mL-1 to 5 µg mL-1. The detection limit of the biosensor was calculated at levels down to 6.33 × 10-8 g mL-1 (3σ). The proposed ECL sensor was successfully used in the detection of trypsin in serum samples. The results reveal a novel quenching effect of BP nanomaterials on ECL, which will further expand its application in ECL biosensing for proteins.

Selective Recovery and Detection of Gold with Cucurbit[n]urils (n = 5-7).

Environmentally benign methods for gold recovery and detection are highly desirable for a sustainable future. Herein, we demonstrate a selective recovery and detection strategy of gold with cucurbit[n]urils (Q[n = 5-7]) by means of outer-surface interactions. Tetrachloroaurate anion ([AuCl4]-) is able to be rapidly precipitated with Q[n] in forms of supramolecular adducts. X-ray crystallography of four Q[n = 5-7]·[AuCl4]- complexes reveal that strong outer-surface interactions between Q[n = 5-7] and [AuCl4]- are the major driving force for the formation of Q[n = 5-7]·[AuCl4]- complexes. Impressively, each Q[6] macrocycle is surrounded by 12 [AuCl4]- anions. Each of these 12 [AuCl4]- anions is connected to four adjacent [AuCl4]- anions, leading to the formation of a three-dimensional supramolecular framework with tubular channels. In addition, we found an interesting inclusion complex [Au(OH2)4]3+⊂Q[7] in the Q[7]·[AuCl4]- complex, which is the first example of hydrated metal cation encapsulated inside the cavity of Q[n]. Spectroscopic data suggest that Q[n = 5-7] possess a high affinity and selectivity for [AuCl4]- even in the presence of other transition-metal ions. Q[n] modified electrodes are found to be an effective material for the detection of trace gold in dilute solutions.

Electrogenerated chemiluminescence of black phosphorus nanosheets and its application in the detection of H2O2.

Black phosphorus nanosheets (BPNS) were synthesized from BP crystals through liquid exfoliation coupled with ultrasonic methods under aqueous conditions. The morphology of the synthesized BPNS was characterized by TEM, XPS, AFM, Raman spectroscopy, UV-vis absorption and fluorescence spectroscopy, respectively. The obtained BPNS exhibited a multilayer structure and the lateral length was around 300 nm, and could emit fluorescence at 380 nm. A BPNS modified glassy carbon electrode (BPNS/GCE) was fabricated and a strong anodic electrogenerated chemiluminescence (ECL) signal was obtained at the modified electrode with tripropylamine (TPrA) as a coreactant under neutral conditions. Hydrogen peroxide exhibited an apparent inhibiting effect on the anodic ECL signal, and can be sensitively detected. In the range of 1-1000 nM, the decreased ECL intensities varied linearly with the logarithm of the H2O2 concentration, and the detection limit was calculated as 0.96 nM (3σ). The proposed modified electrode exhibited high sensitivity and good stability. The results revealed a new character of BPNS in ECL investigation, and the potential application of 2D nanocomposites in the ECL sensing field.

Electrogenerated chemiluminescence of Ru(bpy)32+ at a black phosphorus quantum dot modified electrode and its sensing application.

Black phosphorus quantum dots (BPQDs) with an average size of 8.2 nm were synthesized through a liquid exfoliation method. The surface morphology and the thickness of the BPQDs were identified by high-resolution transmission microscopy (HRTEM), atomic force microscopy (AFM), and Raman spectroscopy. The electrogenerated chemiluminescence (ECL) behavior of Ru(bpy)32+ was investigated at a BPQD modified glassy carbon electrode under neutral conditions. A strong anodic ECL signal was obtained at the modified electrode in the absence of a coreactant, which is nearly three orders of magnitude larger than that at the bare electrode. Electrochemical results revealed that the oxidation process of Ru(bpy)32+ can be significantly catalyzed by BPQDs, suggesting that BPQDs can act as the coreactant of Ru(bpy)32+ to generate strong light emission. Dopamine could react with the oxidation product of Ru(bpy)32+ and exhibited an apparent inhibiting effect on ECL emission. As a result, it can be sensitively detected in the range of 0.1 nM to 50 nM with a detection limit of 0.022 nM. The present work revealed that BPQDs are a potential ECL platform, and which are promising in the fabrication of a novel ECL biosensor.

Electrogenerated Chemiluminescence Resonance Energy Transfer between Ru(bpy)3(2+) Electrogenerated Chemiluminescence and Gold Nanoparticles/Graphene Oxide Nanocomposites with Graphene Oxide as Coreactant and Its Sensing Application.

In the present work, strong anodic electrogenerated chemiluminescence (ECL) of Ru(bpy)3(2+) was observed at a graphene oxide modified glassy carbon electrode (GO/GCE) in the absence of coreactants. The electrocatalytical effect of GO on the oxidation of Ru(bpy)3(2+) suggested that GO itself can act as the coreactant of Ru(bpy)3(2+) ECL, which can be used to fabricate the ECL biosensor. Thiol group terminated adenosine triphosphate (ATP) aptamer was immobilized on the GO film via DNA hybridization. When gold nanoparticles/graphene oxide (AuNPs/GO) nanocomposites were modified on the aptamer through the S-Au bond to form a sandwich-like structure, the ECL resonance energy transfer (ECL-RET) could occur between Ru(bpy)3(2+) and AuNPs/GO nanocomposites, resulting in an apparent decrease of ECL signal. After the ECL sensor was incubated in ATP solution, the AuNPs/GO nanocomposites were released from the electrode due to the specific interaction between aptamer and ATP, leading to the increased ECL signal. On the basis of these results, an ECL aptasensor was fabricated and could be used in the sensitive and selective detection of ATP in the range of 0.02-200 pM with a detection limit of 6.7 fM (S/N = 3). The proposed ECL aptasensor can be applied in the detection of ATP in real samples with satisfactory results.

Electrochemiluminescent Sensing for Caspase-3 Activity Based on Ru(bpy)3(2+)-Doped Silica Nanoprobe.

Caspase-3 is one of the most frequently activated cysteine proteases during the apoptosis process and has been identified as a well-established cellular marker of apoptosis. In this study, a novel approach for the sensitive determination of caspase-3 activity was proposed using electrochemiluminescence (ECL) of Ru(bpy)3(2+)-doped silica (Ru@SiO2) with tripropylamine (TPA) as coreactant. A nanocomposite containing gold nanoparticles (AuNPs), poly(dimethyldiallyl ammonium chloride) (PDDA), and multiwalled carbon nanotubes (CNTs) was fabricated as an ECL platform. The biotinylated DEVD-peptide (biotin-Gly-Asp-Gly-Asp-Glu-Val-Asp-Gly-Cys) was immobilized on the nanocomposite surface via the strong bonding interaction between AuNPs and the thiol group. Then the streptavidin-modified Ru(bpy)3(2+)-doped silica (Ru@SiO2-SA) was immobilized on the ECL platform via the specific interaction between biotin and streptavidin to generate ECL signal. Caspase-3 can specifically recognize and cleave the N-terminus of DEVD, leading to the loss of the biotin label and the decrease of ECL intensity to determine the activity of caspase-3. The results revealed a new ECL avenue for the sensitive and specific monitor of caspase-3, and the platform could be utilized to evaluate anticancer drugs.

Electrogenerated chemiluminescence resonance energy transfer between luminol and CdSe@ZnS quantum dots and its sensing application in the determination of thrombin.

In this work, electrogenerated chemiluminescence resonance energy transfer (ECL-RET) between luminol as a donor and CdSe@ZnS quantum dots (QDs) as an acceptor was reported in neutral conditions. It was observed that a glassy carbon electrode modified with CdSe@ZnS quantum dots (CdSe@ZnS/GCE) can catalyze the luminol oxidation to promote the anodic luminol ECL without coreactants. The intensity of anodic luminol ECL (0.60 V) at the CdSe@ZnS/GCE was enhanced more than 1 order of magnitude compared with that at the bare GCE. Another stronger anodic ECL peak observed at more positive potential (1.10 V) could be assigned to the ECL-RET between the excited state of luminol and the QDs. A label-free ECL aptasensor for the detection of thrombin was fabricated based on the synergic effect of the electrocatalysis and the ECL-RET. The approach showed high sensitivity, good selectivity, and wide linearity for the detection of thrombin in the range of 10 fM-100 pM with a detection limit of 1.4 fM (S/N = 3). The results suggested that the as-proposed luminol-QDs ECL biosensor will be promising in the detection of protein.

Sensitive detection of kanamycin based on ECL resonance energy transfer between iridium complex doped SiO2 nanospheres and Au nanoparticles decorated TiVC MXene.

Herein, a novel sandwich electrochemiluminescence (ECL) aptasensor was developed based on the resonance energy transfer (RET) with iridium complex doped silicate nanoparticles (SiO2@Ir) as energy donor and gold nanoparticles modified TiVC MXene (AuNPs@TiVC) as energy acceptor. Strong anodic ECL signal of SiO2@Ir was obtained through both co-reactant pathway and annihilation pathway. Electrochemical results showed that SiO2@Ir has good electron transfer rate and large specific surface area to immobilize more aptamers. AuNPs@TiVC apparently quenched the ECL signal of SiO2@Ir due to the ECL resonance energy transfer between them. In the presence of kanamycin (KAN), a sandwich type sensor was formed with the aptamer probes as connecters between the donor and the acceptor, resulting in the decrease of ECL intensity. Under the optimal condition, KAN could be sensitively detected in the range of 0.1 pg/mL to 10 ng/mL with a low detection limit of 24.5 fg/mL. The proposed ECL system exhibited satisfactory analytical performance, which can realize the detection of various biological molecules by adopting suitable aptamer.

Coreactant-free strong Ru(bpy)32+ ECL at ionic liquid modified electrode and its application in sensitive detection of glucose based on resonance energy transfer.

In this work, we have realized the strong anodic ECL emission of Ru(bpy)32+ at ionic liquid (N-butylpyridinium tetrafluoroborate) modified electrode without additional coreactant. Methylene blue (MB) could accept the energy of Ru(bpy)32+ ECL to construct resonance energy transfer (ECL-RET) system, leading to the decrease of ECL signal. In the presence of glucose oxidase, hydrogen peroxide generated from the oxidation process of glucose could oxidize MB and block the ECL-RET route, resulting in the recovery of ECL signal. As a consequence, the designed sensor showed outstanding performance for "signal-on" detection of glucose in the concentration range of 10 µM to 1 mM, and the detection limit was determined as 1.75 µM. Importantly, this study revealed new roles of ILs in the fabrication of coreactant-free ECL sensing, which might open up a promising route for the potential design and implement in clinical analysis.

Ligand-Enabled ortho-Selective C-H Olefination of Tertiary Aniline Derivatives.

A highly ortho-selective CAr-H olefination of tertiary anilines without a directing group was developed. This reaction tolerated various substituted arenes and olefin coupling partners, affording ortho-olefination products in moderate to good yields. Preliminary mechanistic studies showed that N-Ac-d-Ala, Ag2CO3, and BQ were the key factors for tuning the regioselectivity from para to ortho. Density functional theory was used to achieve a theoretical understanding of the ortho selectivity.

Electrogenerated chemiluminescence of bismuth sulfide nanorods modified electrode in alkaline aqueous solution.

Electrogenerated chemiluminescence (ECL) behavior of a bismuth sulfide nanorods modified glassy carbon electrode (NR-GCE) was investigated in alkaline aqueous solution for the first time. One weak ECL peak of the NR-GCE was observed around -1.70 V when the electrode potential was scanned from 0.0 V to -2.0 V. The intensity of the ECL peak was enhanced greatly in the presence of either H2O2 or persulfate. The dissolved oxygen, the pH and the supporting electrolytes of the working solution could influence ECL emission noticeably. Under the optimal conditions, the ECL signal displayed a good linear relationship with the concentration of hydrogen peroxide in the range of 5.0 × 10(-7) to 1.0 × 10(-4) mol L(-1) with a correlation coefficient of 0.997 and a detection limit of 2.0 × 10(-7) mol L(-1) at the signal-to-noise ratio of 3. A possible ECL mechanism of the NR-GCE was also proposed.