Electrochemiluminescence Sensor Research Articles

A magnetically fixed bifunctional monomer molecularly imprinted electrochemiluminescence sensor for specifically identifying thiabendazole in food

A magnetically fixed bifunctional monomer molecularly imprinted electrochemiluminescence (ECL) sensor (MIP/MMOF@g-C3N4/L-Aas/MGCE) was constructed to selective detection thiabendazole (TBZ). Fe3O4 modified by sulfonic acid group (–SO3H) acted as magnetic core to attract Co2+ to initiate the growth of ZIF-67 (MMOF). Graphitic carbon nitride nanosheets (g-C3N4) were doped into MMOF by inherent amino groups to prepare integrated magnetic ECL luminophore (MMOF@g-C3N4). MMOF@g-C3N4 was immobilized on the surface of magnetic glassy carbon electrode (MGCE) by using the superparamagnetism of Fe3O4, which enhanced the stability and reusability of ECL system. Sodium ascorbate (L-Aas) acted as co-reactant accelerators to further enhance ECL intensity. MIP prepared with TBZ as template molecule and o-phenylenediamine (oPD)/resorcinol (RS) as bifunctional monomers contained more imprinting sites, which can enhance the adsorption performance. The luminescence mechanism of magnetic ECL system was investigated, and the specific recognition mechanism of MIP recognition system was deeply explored. The linear range of the method was 1 × 10−9–5 × 10−5 mol L−1, and the detection limit was 3.77 × 10−10 mol L−1. A good recovery rate (80.08%–96.82%) was obtained in the actual sample detection, which was basically consistent with the detection results of High Performance Liquid Chromatography.

Dual-ligand Eu-MOF/CuS@Au Heterostructure Array-based ECL Sensor for MiRNA-128 Detection in Glioblastoma Tissues

In this work, the dual-ligand lanthanide metal-organic framework (MOF)-based electrochemiluminescence (ECL) sensor was constructed for the detection of miRNA-128 in glioblastoma (GBM) diagnosis. The luminescent Eu-MOF (EuBBN) was synthesized with terephthalic acid (BDC) and 2-amino terephthalic acid (BDC-NH2) as dual-ligand. Due to the antenna effect, EuBBN with conjugated-π structure exhibited strong luminescent signal and high quantum efficiency, which can be employed as ECL nanoprobe. Furthermore, the novel plasmonic CuS@Au heterostructure array has been prepared. The localized surface plasmon resonance coupling effect of the CuS@Au heterostructure array can amplify the ECL signal of EuBBN significantly. The EuBBN/CuS@Au heterostructure array-based sensing system has been prepared for the detection of miRNA-128 with a wide linear range from 1 fM to 1 nM and a detection limit of 0.24 fM. Finally, miRNA-128 in the clinic GBM tissue sample has been analysis for the distinguish of tumor grade successfully. The results demonstrated that the dual-ligand MOF/CuS@Au heterostructure array-based ECL sensor can provide important support for the development of GBM diagnosis.

Timescale correlation of shallow trap states increases electrochemiluminescence efficiency in carbon nitrides

Highly efficient interconversion of different types of energy plays a crucial role in both science and technology. Among them, electrochemiluminescence, an emission of light excited by electrochemical reactions, has drawn attention as a powerful tool for bioassays. Nonetheless, the large differences in timescale among diverse charge-transfer pathways from picoseconds to seconds significantly limit the electrochemiluminescence efficiency and hamper their broad applications. Here, we report a timescale coordination strategy to improve the electrochemiluminescence efficiency of carbon nitrides by engineering shallow electron trap states via Au-N bond functionalization. Quantitative electrochemiluminescence kinetics measurements and theoretic calculations jointly disclose that Au-N bonds endow shallow electron trap states, which coordinate the timescale of the fast electron transfer in the bulk emitter and the slow redox reaction of co-reagent at diffusion layers. The shallow electron trap states ultimately accelerate the rate and kinetics of emissive electron-hole recombination, setting a new cathodic electrochemiluminescence efficiency record of carbon nitrides, and empowering a visual electrochemiluminescence sensor for nitrite ion, a typical environmental contaminant, with superior detection range and limit.

A molecule-imprinted electrochemiluminescence sensor based on CdS@MWCNTs for ultrasensitive detection of fenpropathrin.

A molecularly-imprinted electrochemiluminescence sensor was constructed for the determination of fenpropathrin (FPT) by molecular imprinting technology. In this sensing platform, the introduction of CdS@MWCNTs significantly enhanced the initial ECL signal of the luminol-O2 system. Specifically, MWCNTs was used as a carrier to adsorb more CdS, in which CdS acted as a co-reaction promoter for luminescence. Molecularly imprinted polymer (MIP) containing specific recognition sites of FPT was used as the material for selective recognition. With increasing amount of FPT the ECL signal decreased. Under the optimum conditions, the ECL response was linearly related to the logarithm of FPT concentration. The developed ECL sensor allowed for sensitive determination of FPT and exhibited a wide linear range from 1.0 × 10- 10 mol L- 1 to 1.0 × 10- 6 mol L- 1. The limit of detection was 3.3 × 10- 11 mol L- 1 (S/N = 3). It can be used for the detection of FPT in vegetable samples.

Molecular imprinting-based Ru@SiO2-embedded covalent organic frameworks composite for electrochemiluminescence detection of cyanidin-3-O-glucoside

Cyanidin-3-O-glucoside (C3G), a natural antioxidant, plays multiple physiological or pathological roles in maintaining human health; thereby, designing advanced sensors to achieve specific recognition and high-sensitivity detection of C3G is significant. Herein, an imprinted-type electrochemiluminescence (ECL) sensing platform was developed using core-shell Ru@SiO2-CMIPs, which were prepared by covalent organic framework (COF)-based molecularly imprinted polymers (CMIPs) embedded in luminescent Ru@SiO2 cores. The C3G-imprinted COF shell not only helps generate a steady-enhanced ECL signal, but also enables specific recognition of C3G. When C3G is bound to Ru@SiO2-CMIPs with abundant imprinted cavities, resonance energy transfer (RET) behavior is triggered, resulting in a quenched ECL response. The constructed Ru@SiO2-CMIPs nanoprobes exhibit ultra-high sensitivity, absolute specificity, and an ultra-low detection limit (0.15 pg mL−1) for analyzing C3G in food matrices. This study provides a means to construct an efficient and reliable molecular imprinting-based ECL sensor for food analysis.

An electrochemiluminescence sensor based on Ag NPs amplifying PDDA-modified TbPO4:Ce NWs signal for sensitive detection of lincomycin

The residue of lincomycin in water will not only aggravate the drug resistance of bacteria but also cause damage to the human body through biological accumulation. In this work, an electrochemiluminescence (ECL) aptasensor for the detection of lincomycin was constructed based on polydimethyldiallylammonium chloride (PDDA) functionalized Ce-doped TbPO4 nanowires (PDDA-TbPO4:Ce NWs) and silver nanoparticles (Ag NPs). TbPO4:Ce NWs were used as the luminophore, and PDDA was used to functionalize the luminophore to make the surface of the luminophore positively charged. The negatively charged silver nanoparticles were combined with PDDA-TbPO4:Ce NWs by electrostatic interaction. Ag NPs accelerated the electron transfer rate and promoted the ECL efficiency, which finally increased the ECL intensity of TbPO4:Ce NWs by about 4 times. Under the optimal conditions, the detection limit of the ECL sensor was as low as 4.37 × 10−16 M, and the linear range was 1 × 10 − 15 M to 1 × 10 − 5 M, with good selectivity, stability, and repeatability. The sensor can be applied to the detection of lincomycin in water, and the recovery rate is 97.7–103.4 %, which has broad application prospects.

Dual-potential ratiometric electrochemiluminescence based on single emitter and single coreactant for the sensitive detection of carcinoembryonic antigen

Dual-potential ratiometric electrochemiluminescence (ECL) is in favor of resistance to environmental interference. However, two kinds of emitters or coreactants, and a wide scan potential range (>2 V) are mandatory. This work developed a new dual-potential ratiometric ECL sensor for detection of carcinoembryonic antigen (CEA) using single emitter (luminol) and single coreactant (H2O2) with a mild potential range from −0.1 to 0.6 V. Luminol could produce a strong cathodic ECL (Ec) induced by hydroxyl radicals (HO‧) from the reduction of H2O2, and a relatively weak anodic ECL (Ea). After the ferrocene modified CEA aptamer (Apt-Fc) was attached, Fc could promote Ea by catalyzing the oxidation of H2O2, and reduce Ec by consuming HO‧. With the cycling amplification of the exonuclease I, CEA could substantially reduce the amount of Apt-Fc, resulting in the decrease of Ea and the rise of Ec. So, the ratio of Ec to Ea (Ec/Ea) was used as the detection signal, realizing the sensitive determination of CEA from 0.1 pg mL−1 to 10 ng mL−1 with a LOD of 41.85 fg mL−1 (S/N = 3). The developed sensor demonstrated excellent specificity, stability and reproducibility, with satisfactory results in practical detection.

Simple and ultrasensitive solid-state electrochemiluminescence sensor based on g-C3N4 and Au NPs for detection of Doxorubicin

A simple and ultrasensitive solid-state electrochemiluminescence (ECL) sensor was developed for the detection of doxorubicin (DOX). The sensor was constructed by coating the electrode with graphitic carbon nitride (g-C3N4) and a complex substance called Au NPs@HAP@CS, which consists of Au nanoparticles (Au NPs), hydroxylaptite (HAP), and chitosan (CS). The luminescent reagent, g-C3N4, obtained from high temperature pyrolysis of melamine, produced a relatively sensitive but unstable ECL signal in a K2S2O8 solution (pH 8.0). The introduced Au NPs, with their high negative potential, enhanced electron transport and captured and store excess electrons injected into g-C3N4, thereby improving the ECL signal and its stability. The non-toxic green HAP, serving as a carrier of Au NPs, further enhanced the ECL signal, and the addition of CS improved the stability of the sensor. Under optimal conditions, the fabricated ECL sensor demonstrated sensitive determination of DOX, with a linear range of 5.0 × 10−15 ∼ 1.0 × 10−8 mol/L and a detection limit as low as 1.67 × 10−15 (S/N = 3). Notably, the resulting sensor exhibited good stability, high sensitivity, and reliable reproducibility, making it suitable for the detection of trace DOX in human serum.

Self-enhanced luminescence of copper nanowires combined with pH-sensitive glycosyl imprinted polymers: Electrochemiluminescence for high-sensitivity detection of sialic acid

It is of great significance to explore a low cost and high sensitivity sialic acid (SA) detection method for early diagnosis and prognosis of cancer. Electrochemiluminescence (ECL) has aroused many scholars' interest in the accurate analysis of multi-domain analytes for its excellent performance. In order to improve the ECL signal strength and the corresponding detection sensitivity, it is effective to develop new ECL reagents. Copper nanowires (CuNWs) as luminophor has always been a blank in the field of ECL sensors. In this study, a glycosyl imprinted electrochemiluminescence sensor (GIP-ECLS) for SA specificity detection in serum was developed using CuNWs as luminophor. CuNWs can not only form quasi-three-dimensional (3D) conductive network, but also realize self-enhancement of ECL signal through Cu2+ and Cu+ conversion. In addition, the excellent conductivity and wrapping properties of Ti3C2 provide a large electroactive area for electrode modification. More importantly, 3-aminobenzenoboric acid (3-ABA) specifically binds to SA to form B-N or B-O, which lays the foundation for selective recognition of SA. Under optimal conditions, the signal response of GIP-ECLS showed a good linear relationship with SA concentration at 5 × 10−12–1 × 10−8 mol L−1 (R2 = 0.997), and the limit of detection (LOD) was 1.17× 10−12 mol L−1. The results showed that in the actual sample analysis, the recovery rate of SA detected by GIP/Ti3C2/CuNWs/GCE was good, and it had good selectivity and stability, which provided ideas for designing minimally invasive and highly sensitive detection of SA in serum samples.

Electrochemiluminescent properties of carbon nitride nanoflowers and their application to the detection of melatonin in foods

Carbon nitride nanoflower materials (CNNFs) modified electrodes were prepared and used as electrochemiluminescence (ECL) sensors for the sensitive detection of melatonin (MT) in food. The luminescence intensity of CNNFs is increased by 4.6 times compared with bulk g-C3N4. In addition, the effect of dissolved oxygen on the material was eliminated, and the stability of ECL intensity of CNNFs was improved. Under the optimal experimental conditions, there is a good linear relationship between the ECL intensity ratio and logCMT in a concentration range of 2.0 × 10−11–1.0 × 10−6 mol/L, and the detection limit is 6.2 × 10−13 mol/L. This experiment has been successfully used for the detection of MT in rice, black rice, oats, apples, bananas, grapes, carrots, tomatoes, cucumbers, bread, and beers. The results are consistent with those obtained by high-performance liquid chromatography (HPLC). Therefore, this sensor is a sensitive and effective method for detecting MT content in food.

Electrochemiluminescence detection of catechol and tryptophol using nitrogen, sulfur co-doped graphene quantum dots based on a paper-based sensor

In this study, Nitrogen and Sulfur co-doped Graphene Quantum Dots (N, S-GQDs) were synthesized via a pyrolysis approach, utilizing citric acid as the carbon source and L-cysteine as the nitrogen and sulfur sources. These N, S-GQDs were used to develop a novel paper-based electrochemiluminescence (ECL) sensor for the detection of catechol (CC) and tryptophol, two potentially hazardous substances in the environment. Screen printing technology was utilized to construct the ECL sensor on filter paper, incorporating a hydrophobic layer, working and counter electrodes, and a reference electrode. The presence of CC and tryptophol was found to result in a decrease in the ECL intensity of the quantum dots (QDs), this quenching phenomenon is attributed to the oxidation of these substances within the electrochemical system and the subsequent electron transfer from the excited state of the QDs to the oxidation products. The sensor demonstrated a linear detection range for CC and tryptophol from 0.01 to 1000 μM, with detection limits of 0.0082 μM and 0.0066 μM, respectively, and exhibited excellent selectivity, stability, and repeatability. This cost-effective and efficient monitoring technique holds significant promise for environmental and health safety by facilitating the detection of CC and tryptophol, thereby mitigating their potential adverse impacts.

An electrochemiluminescence sensor based on lanthanide bimetallic MOFs with a “cascade sensitization mechanism” for the sensitive detection of CA242

Lanthanide metal-organic frameworks (Ln-MOFs) broaden the optical sensing applications of lanthanide ions due to the antenna effect between organic ligands and metals. However, the sensitization ability of the ligand to metal ions is limited, and maximizing the sensitization of the electrochemiluminescence behavior of Eu3+ is still a challenge for the application of Ln-MOFs. Therefore, under the guidance of the “cascade sensitization mechanism” based on the antenna effect sensitizing the electrochemiluminescence of bimetallic Ln-MOFs, we proposed Eu/Tb-MOFs with high luminescence intensity as a signal probe. According to the antenna effect, the conjugated structure and high extinction coefficient of the benzene ring of 2-amino terephthalic acid (NH2-BDC) can enhance the ECL luminescence intensity of Eu/Tb-MOFs. Tb3+ can act as an energy bridge between NH2-BDC and Eu3+, buffering the energy gap. The bimetallic sensitization is formed between Tb3+ and Eu3+, which can inhibit the reverse internal flow of energy and ensure the high luminous efficiency of Eu3+. In addition, the nanosphere mixed valence Fe3O4 as a co-reactant accelerator promotes the formation of transient free radical SO4•- through the valence change of Fe2+/Fe3+. The ECL immunosensor constructed by luminophores Eu/Tb-MOFs and nanosphere Fe3O4 provided a new explanation for the ECL self-luminous of Eu/Tb-MOFs.

Ultrasensitive solid-state electrochemiluminescence sensor based on lotus root shaped carbon fiber, CdSe QDs and Fe3O4 synergically amplify Ru(bpy)32+ luminophore signal for detection of cyfluthrin.

An efficient and innovative electrochemiluminescence (ECL) sensor was developed for trace detection of cyfluthrin.The sensor utilized materials such as lotus root shaped carbon fiber (Co CNFs), cadmium selenide quantum dots (CdSe QDs), and Fe3O4 to amplify Ru(bpy)32+ signals. Co CNFs, with its large specific surface area and porosity, served the purpose of not only enhancing the stability of the sensor by fixing CdSe QDs and Ru(bpy)32+ on the Co CNFs/GCE, but also facilitating electron transfer. CdSe QDs was involved in the luminescence reaction and collaborated with Ru(bpy)32+ to enhance the sensor's sensitivity, while Fe3O4 promoted electron transfer in the system due to its large surface area. The solid-state ECL sensor achieved satisfactory signal under the synergistic action of these components. The ECL signal of the sensor was quenched by cyfluthrin, and a favorable linear relationship was observed between the sensor and cyfluthrin in the concentration range 1 × 10-12 to 1 × 10-6 M. The detection limit of the sensor was 3.3 × 10-13 M (S/N = 3). The utilization of lotus root shaped carbon fiber, CdSe QDs, and Fe3O4 in the Ru(bpy)32+ system demonstrated a synergistic effect for cyfluthrin detection, presenting a new approach for the rapid determinationanalysis of pesticide residues in foods.

Charge Density-Regulated Microchannel-Based Electrochemiluminescence Sensor for Hydrogen Sulfide Detection with a Highly Efficient Accumulation Strategy.

The electrochemiluminescence (ECL) intensity can be regulated by ionic current passing through the microchannel, which broadened the regulation of the ECL sensors. But in the early reported sensors, the electrostatic repulsion and steric hindrance caused few targets to approach the interface of the microchannel driven by concentration difference, which reduced the detection efficiency and prolonged the detection period. In this study, different accumulation strategies, such as a positive electric field and different polarity electric fields, were designed to accumulate targets in the microchannel. The interaction of azide groups and hydrogen sulfide served as a research model. Hydrogen sulfide can react with the negatively charged azide groups in the microchannel surface to produce positively charged amino groups, decreasing the negative charge density of the microchannel and thus altering the ionic current and ECL intensity. The accumulation of hydrogen sulfide at the microchannel tip can increase the collision probability with azide groups to improve the detection efficiency, and the integration of accumulation and reaction can shorten the detection period to 28 min. The hydrogen sulfide concentration on the microchannel tip accumulated by applying different polarity electric fields was 22.3-fold higher than that accumulated by applying a positive electric field. The selected research model broadened the application range of a microchannel-based ECL sensor and confirmed the universality of the microchannel-based ECL sensor.

Strong cathode electroluminescence biosensor based on CeO2 functionalized PCN-222@Ag NPs for sensitive detection of p-Tau-181 protein

Electrochemiluminescence (ECL) biosensors provide a convenient and high sensitivity method for early disease diagnosis. However, creating luminophore arrays relying on powerful ECL signals remains a daunting task. Porphyrin-centered metal organic frameworks (MOFs) exhibit remarkable potential in ECL sensing applications. In this paper, based on a simple one-pot synthesis method, PCN-222@Ag NPs doped with CeO2 was synthesized to enhance the ECL performance. Due to the strong catalytic ability of CeO2, the ECL signal strength of the new material PCN-222@CeO2@Ag NPs is much higher than that of the PCN-222@Ag NPs and PCN-222. The luminous properties of PCN-222@CeO2@Ag NPs become more intense and stable due to the excellent electronic conductivity of Ag NPs. Based on the fact that CuS@PDA composite can quench the ECL signal of PCN-222@CeO2@Ag NPs, we constructed a novel sandwich ECL immune sensor for the detection of phosphorylated Tau 181 (p-Tau-181) protein. The ECL sensor has a great linear relationship with p-Tau-181 protein concentration, ranging from 1 pg/mL to 100 ng/mL. The detection limit is as low as 0.147 pg/mL. This work provides new ideas for developing sensitive ECL sensors for the p-Tau-181 protein, the marker of Alzheimer's disease.

Nanocluster/metal-organic framework nanosheet-based confined ECL enhancement biosensor for the extracellular vesicle detection

Gastric cancer (GC) was one of the most common cancers with high mortality. The detection of GC peritoneal metastasis had important significance. In this work, we have developed the novel electrochemiluminescence (ECL) biosensor to detect microRNA in GC extracellular vesicle (EV). Firstly, in situ growth of Cu nanocluster (Cu NC) on the metal-organic frameworks (MOFs) nanosheet was achieved successfully. Due to the confinement effect, Cu NCs in the porous structure of Zn MOF possessed the high quantum yield and good stability. Meanwhile, Zn MOF provided good electrochemical activity for the ECL reaction. Furthermore, the nanosized MOFs did not only act as sensing platform to load Cu NCs and link biomolecules, but also reduce steric hindrance effect for biomolecular recognition. Additionally, Au NPs/MXene and phospholipid layer were prepared and modified on the electrode, which can regulate electron transfer and improve the target recognition efficiency. The Cu NCs/Zn MOF nanosheet-based ECL sensor was employed to detect miRNA-421 from 1 fM to 1 nM with a detection limit of 0.5 fM. Finally, extracellular vesicles form clinic GC patient ascites were extracted and analyzed. The results showed that the constructed biosensor can be used for the GC peritoneal metastasis diagnosis.

Electrochemiluminescence detection of diazinon in vegetables based on the synergistic interaction of WO3-x dots with Au@SiO2 nanocapsules

In this work, a simple synthesis of low-toxicity transition metal material of WO3-x dots was used as a co-reactant with Au@SiO2 as a core-shell material and a signal amplification factor to collaboratively promote Ru(bpy)32+ electrochemiluminescence (ECL) for the construction of a highly sensitive aptasensor for the detection of diazinon (DZN) in vegetables. Electrodes modified with multi-walled carbon nanotubes-chitosan composite membranes (MWCNTs-CS) were used to load and immobilize more Ru(bpy)32+.can load more Ru(bpy)32+. WO3-x dots synthesized by a simple method showed excellent ECL efficiency as a novel co-reactant for Ru(bpy)32+. Under optimized conditions, this aptasensor for DZN has a wide detection range (10 pg mL−1 - 1 μg mL−1.) and a low detection limit (0.0197 ng L−1). The aptasensor has shown good results in the analysis of real samples in the experiment. This work provides a new approach to the construction of a novel electrochemiluminescence sensor for the detection of pesticides.

A dual-mode biosensor based on silica inverse opal photonic crystals modulated electrochemiluminescence and dye displacement colorimetry for the sensitive detection of synthetic cathinone in water environment

To address the challenges posed by signal capacity limitations and the reliance of sensing methods on single analytical information, this study developed an electrochemiluminescence (ECL) and colorimetric dual-mode sensing platform for the precise detection of 4-chloroethcathinone (4-CEC) in water environments. Firstly, the accurate alignment of the reflection wavelength of appropriately sized silica inverse opal photonic crystals (SIOPCs) with the ECL emission wavelength of luminescent metal-organic frameworks (PCN-224) has been achieved via diameter modulation. This innovative design, which cleverly utilized the band-edge effect, improved the luminous intensity of the ECL sensor, leading to a significant boost in analytical performance. Secondly, the establishment of a colorimetric detection method for confirming the presence of 4-CEC in samples through visual observation of color changes was achieved by employing an aptamer-based dye displacement reaction, utilizing differential binding affinities between the aptamer and both the sulforhodamine B (SRB) and 4-CEC. Under the optimal experimental conditions, the dual-mode sensor demonstrated ECL detection of limits (LOD) of 2.6 × 10−13 g/L and colorimetric LOD of 6.5 ng/L for 4-CEC. These findings highlighted the tremendous potential of developing streamlined and efficient dual-signal readout platforms using ECL aptamer sensors for the precise determination of other Synthetic cathinones (SCs) in water environments.

Dual-source signal amplification electrochemiluminescence sensor combined with molecularly imprinted polymers for the imidacloprid detection

A novel lanthanide metal-organic-gel (MOG)-derived material/nitrogen-doped graphdiyne (Tb-Ru-MOG/CeO2/N-GDY) composite with a dual-source signal amplification strategy was prepared and used to construct a molecularly imprinted sensor based on bifunctional monomers for the detection of imidacloprid (IMI) using electrochemiluminescence (ECL). In a green reaction environment, terbium (III) (Tb3+) can undergo multiple coordination reactions with 4′-(4-carboxyphenyl)-2,2′:6′,2″-terpyridine (Hcptpy) and tris(4,4′-dicarboxylicacid-2,2′-bipyridyl) ruthenium (II) dichloride (Ru(dcbpy)32+), and combine with ceria nanoparticles (CeO2 NPs) to form Tb-Ru-MOG/CeO2. Within the Tb-Ru-MOG/CeO2 framework, energy transfer from the double ligands can sensitize the central Tb3+, triggering a distinct antenna effect and energy-transfer, and its polyporous configuration offered a nanoconfined space for Ce3+/Ce4+ to effectively catalyze coreactant radicals (S2O82−), leading to in-situ endogenous activation ECL reactions. The conductive N-GDY accelerated electron movement and increased the loading on the electrode surface, enhancing the exogenous excitation of the ECL signals. Leveraging the synergistic effect of the bifunctional monomer, the synthesized molecularly imprinted polymers (MIPs) ECL sensor demonstrated a wide detection range from 10 nM to 10,000 nM for IMI, with a limit of detection (LOD) of 1.37 nM, showcasing an innovative concept for the dual-source strategy of signal amplification in integrated ECL composites to analyze food and environmental hazards.

A sensor based on Fe/B/N codoped hierarchical porous carbon spheres that amplify the aggregation-induced electrochemiluminescence of calcein for florfenicol trace detection

Electrochemiluminescence (ECL) signal amplification is an important method for improving sensor sensitivity. In this study, an ECL sensor was developed for florfenicol detection based on the aggregation-induced electrochemiluminescence of calcein and Fe/B/N codoped hierarchical porous carbon spheres (B-N-Fe-HPCs). First, B-N-Fe-HPCs were prepared by a simple high-temperature synthesis method, attached to the gold electrode surface, and used as a signal amplification element. Then, a molecularly imprinted polymer (MIP) was prepared using florfenicol as a template molecule and phthalylenediamine as a functional monomer and doped with calcein on the B-N-Fe-HPC-modified electrode. After the elution of florfenicol, the sensor retains an imprinted site that specifically recognizes florfenicol can readsorb florfenicol in the sample. Because calcein aggregates in the MIP to generate an ECL signal, B-N-Fe-HPCs effectively amplifies this ECL signal. Thus, because the ECL signal of the sensor can be quenched, a new method for detecting florfenicol was established. The sensor used for florfenicol showed very high sensitivity and good selective performance, with a linear range of 1–8000 × 10−12 mol/L and a detection limit of 4.65 × 10−13 mol/L. The sensor was applied to detect actual samples, such as chicken, and the results were satisfactory, with the recovery rate of the spike from 91.2 % to 105.3 %.