Solid-state Electrochemiluminescence Research Articles

Solid-state electrochemiluminescence sensor of luminol based on polymer donor PM6 and ZIF-8 for sensitive detection of sunset yellow in sports drinks

Solid-state electrochemiluminescence sensor of luminol based on polymer donor PM6 and ZIF-8 for sensitive detection of sunset yellow in sports drinks

RuSiNPs@N,S-GQDs as self-enhanced anodic electrochemiluminescent immunobeacons for the highly sensitive quantitation of okadaic acid in shellfish.

Acompetitive electrochemiluminescence (ECL) immunosensor isproposed to accurately and rapidly assess okadaic acid (OA) levels in shellfish using a novel self-reinforced solid-state ECL marker, which is essential for ensuring seafood safety. Graphene quantum dots doped with nitrogen and sulfur (N,S-GQDs) were synthesized, for the first time, through the electrolysis of graphite in 3-(N-morpholine) propane sulfonic acid solution. Intriguingly, these N,S-GQDs exhibited exceptional co-reactant properties, significantly enhancing the anodic ECL performance of Ru(bpy)32+ in a phosphate-buffered saline solution. Following the functionalization of Ru(bpy)32+-doped silica nanoparticles (RuSiNPs) with poly(diallyldimethylammonium) chloride, we achieved a well-dispersed assembly of N,S-GQDs on the exterior of the RuSiNPs through electrostatic interactions. Importantly, the core-shell structure of RuSiNPs@N,S-GQDs efficiently encapsulated both the luminophore and co-reactant, thus improving the transfer rates of electrons, shorting interaction distances, and reducing energy loss during light emission. Leveraging this "bright" ECL beacon, theECL immunosensor demonstrated remarkable analytical performance, yielding a low half maximal inhibitory concentration (IC50) of 0.14ngmL-1, an extensive linear range spanning 0.003-40ngmL-1, and impressively low limit of detection of 0.001ngmL-1 for OA determination.

Tailoring a novel all-in-one host-guest solid-state electrochemiluminescence platform for selective detection of spermine using cucurbit-[6]-uril modified [Ru(bpy)3]2+ electrode

Herein, a novel solid-state electrochemiluminescence (ECL) based on electrochemically incorporated [Ru(bpy)3]2+ on nafion modified glassy carbon electrode ([Ru(bpy)3]2+-Nafion/GCE) followed by chemisorption of cucurbit-[6]-uril (CB-[6]) on Ru(bpy)3]2+-Nafion/GCE (as CB-[6]-[Ru(bpy)3]2+-Nafion/GCE) has been developed for selective sensing of spermine (SPM) which belongs to the class of aliphatic biogenic amines and overexpression of SPM is associated with several cancers, particularly “Prostate Cancer” (PCa). Interestingly, the ECL emission of [Ru(bpy)3]2+ be enhanced significantly in the presence of CB-[6] modified [Ru(bpy)3]2+-Nafion/GCE. This is due to inherent ability of CB- [6] act as a co-reactant accelerator. Upon the addition of SPM, the ECL emission was further enhanced due to electron transfer reaction between SPM and [Ru(bpy)3]3+. Selectivity of the proposed ECL sensor towards SPM arises from the host-guest interaction between the CB-[6] and SPM, follows the anodic co-reactant ECL reaction (oxidative reduction mechanism) by confirmation of electrochemical and spectroscopic results like electron spin resonance (EPR) and ECL spectra. The proposed solid-state ECL sensor platform is selectively detect to SPM for a linear range of 10 nM - 5 mM with detection limit (LoD) of 1.4 nM at physiological pH conditions. In addition, the developed ECL platform of CB-[6]-[Ru(bpy)3]2+-Nafion/GCE has been successfully verified to the sensing of SPM in the urine sample, proving the practicability of the proposed sensor is suitable for clinical analysis.

Solid-state Ru(bpy)32+ electrochemiluminescence sensor for trace detection of fenpropathrin using loofah sponge-like carbon nanofibers and CdS.

Loofah sponge-like carbon nanofibers (LF-Co,N/CNFs) were utilized as a carrier for Ru(bpy)32+, and then combined with CdS to create a novel solid-state electrochemiluminescence sensor capable of detecting trace amounts of fenpropathrin. LF-Co,N/CNFs, obtained through the high-temperature pyrolysis of ZIF-67 coaxial electrospinning fibers, were characterized by a loofah-like morphology and exhibited a significant specific surface area and porosity. Apart from serving as a carrier, LF-Co,N/CNFs also functioned as a luminescence accelerator, enhancing the system's luminescence efficiency by facilitating electron transmission and reducing the transmission distance. The inclusion of CdS in the luminescence reaction, in conjunction with Ru(bpy)32+, further boosted the sensor's luminescence signal. The resulting sensor demonstrated a satisfactory signal, with fenpropathrin causing significant quenching of the ECL signal.Under optimized conditions, a linear relationship between the signal quench value and fenpropathrin concentration in the range 1 × 10-12 to 1 × 10-6M was observed, with a detection limit of 3.3 × 10-13M (S/N = 3). This developed sensor ischaracterized by its simplicity, sensitivity, and successful application in detecting fenpropathrin in real samples. The study not only presentsa straightforward detection platform for fenpropathrin but also introduces new avenues for the rapid determinationof various food contaminants, thereby expanding the utility of carbon fibers in electrochemiluminescence sensors.

A signal-on electrochemiluminescence (ECL) sensor based on luminol@carbon nanotubes and CdTe-ZnS@hydroxyapatite for the detection of paclitaxel

A signal-on solid-state electrochemiluminescence (ECL) sensor based on luminol@carbon nanotubes (luminol@CNTs) and CdTe-ZnS@hydroxyapatite (CdTe-ZnS@HAP) was constructed for the detection of paclitaxel (PTX). In this sensing platform, luminol was used as the main luminophore and CdTe-ZnS was used as a co-reaction accelerator. CNTs and HAP were acted as carriers to adsorb more luminophores and co-reaction promoters. In addition, due to the enhanced effect of PTX on the ECL intensity of the luminol-O2 system, PTX was introduced as the final detection target. Under the optimal experimental conditions, the ECL intensity change values (ΔI) of the sensor showed a good linear relationship with the logarithm of PTX concentration in the range of 3 × 10-12 − 3 × 10-7 molL-1, and the limit of detection was 1 × 10-12 mol L-1(S/N = 3). This method was successfully applied to the determination of trace PTX concentration in serum.

An ultrasensitive solid-state electrochemiluminescence sensor based on Ni-MOF@Ru(bpy)32+ and Au NPs@TiO2 for determination of permethrin

The novel TiO2 and Ni-MOF materials were synthesized and utilized for the detection of permethrin (PET). A highly sensitive solid-state electrochemiluminescence (ECL) sensor was developed based on Ni-MOF@Ru(bpy)32+ and Au NPs@TiO2. In this sensing platform, Ru(bpy)32+-Tripropyl Amine (TPrA) was used as a luminescent signal, Ni-MOF acted as a carrier to carry more luminescent reagents Ru(bpy)32+. Au NPs acted as promoters facilitated electron transport and TiO2 could further enhance the luminescence intensity of the system by synergistical interaction with Au NPs. The possible mechanisms of signal amplification were investigated. The ECL intensity decreased significantly with increasing PET concentration, enabling the determination of PET amount through the observation of the change in ECL signal intensity (ΔI). Under optimal experimental conditions, the linear range of PET concentration from 1.0 × 10−11 mol L−1 to 1.0 × 10−6 mol L−1, with a detection limit of 3.3 × 10−12 mol L−1 (3S/N). This method was successfully applied to determine PET in various vegetable samples.

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.

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.

Solid Electrochemiluminescence Sensor by Immobilization of Emitter Ruthenium(II)tris(bipyridine) in Bipolar Silica Nanochannel Film for Sensitive Detection of Oxalate in Serum and Urine.

Convenient and highly sensitive detection of oxalate ions in body fluids is of crucial significance for disease prevention, diagnosis, and monitoring of treatment effectiveness. Establishing a simple solid-state electrochemiluminescence (ECL) sensing system for highly sensitive detection of oxalate ions is highly desirable. In this work, a solid ECL sensor was fabricated by immobilizing the commonly used emitter ruthenium(II)tris(bipyridine) (Ru(bpy)32+) on a double-layered bipolar silica nanochannel array film (bp-SNA)-modified electrode, enabling sensitive detection of oxalate ions in serum or urine samples. Cost-effective and readily available indium tin oxide (ITO) was used as the supporting electrode. Convenient fabrication of multiple negatively charged SNA (n-SNA)-modified ITO electrodes was achieved through the one-step Stöber solution growth method. Subsequently, a positive outer layer film (p-SNA) was rapidly prepared using an electrochemical-assisted self-assembly method. The double-layered bipolar silica nanochannel array film achieved stable immobilization of Ru(bpy)32+ on the electrode surface, facilitated by the electrostatic adsorption of Ru(bpy)32+ by n-SNA and the electrostatic repulsion by p-SNA. Utilizing oxalate ions as a co-reactant for Ru(bpy)32+, combined with the electrostatic enrichment of oxalate ions by p-SNA, the constructed sensor enabled highly sensitive detection of oxalate ions ranging from 1 nM to 25 μM and from 25 μM to 1 mM, with a detection limit (LOD) of 0.8 nM. The fabricated ECL sensor exhibited high selectivity and good stability, making it suitable for ECL detection of oxalate ions in serum and urine samples.

Fabrication of an all-in-one self-enhanced solid-state electrochemiluminescence sensing platform for the selective detection of spermine.

The fabrication of an all-in-one solid-state ECL sensing platform is beneficial not only for expediting the miniaturization of sensing devices, but also, more importantly, for enabling point-of-care applications. In the present work, a self-enhanced solid-state ECL sensing platform is fabricated using newly synthesised silica polyethylene nanoparticles (SiO2-PEI NPs) which generate a co-reactant in situ and easily self-assemble with Ru(bpy)32+ and shows selective and sensitive detection of spermine at physiological pH (7.4). Spermine induces the maximum ECL emission intensity compared to other biogenic amines due to the presence of two secondary amines. A possible ECL reaction mechanism has been proposed based on CV and ECL experiments, DFT calculations, and in situ ECL spectrum analysis. The developed solid-state sensor showed a linear increase in ECL intensity with increasing spermine concentration in the range of 10 nM to 100 nM with an LOD of 12.2 nM. Compared to other biogenic amines in previous works, chemically synthesised SiO2-PEI NPs used in the present study act as an effective label- and enzyme-free sensor, and the new method is observed to be simple and cost-effective, to overcome various limitations of solution-phase ECL and to avoid the usage of any noble metals.

Electrophoretic deposition of Ru(bpy)32+ in vertically-ordered silica nanochannels: A solid-state electrochemiluminescence sensor for prolidase assay

Prolidase (PLD) plays a crucial role as a dipeptidase in various physiological processes, specifically involved in the cleavage of proline-containing dipeptides for efficient recycling of proline. The accurate determination of PLD activity holds significant importance in clinical diagnosis. Herein, a solid-state electrochemiluminescence (ECL) biosensor was developed to address the urgent need for PLD assay. The Ru(bpy)32+ was electrophoretically deposited within the nanochannels of vertically-ordered mesoporous silica film (VMSF) on indium tin oxide (ITO) electrodes. The Ru(bpy)32+-deposited VMSF/ITO (Ru-VMSF/ITO) exhibited a remarkable ECL response towards proline, attributed to the enhanced concentration of the reactants and improved electron transfer resulting from the nanoconfinement effect. As PLD specifically enzymolyzed the Gly-Pro dipeptide to release proline, a proline-mediated biosensor was developed for PLD assay. Increased PLD activity led to enhanced release of proline into the porous solid-state ECL sensors, resulting in a more robust ECL signal. There was a linear relationship between ΔECL intensity and logarithmic concentration of PLD in the range of 10–10000 U/L, with a detection limit of 1.98 U/L. Practical tests demonstrated the reliability and convenience of the proposed bioassay, making it suitable for widespread application in PLD assays.

Solid-state electrochemiluminescence sensor of CQDs based on ZIFs electrospun carbon fiber for malathion detection

In this paper, a novel and simple electrochemiluminescent sensor of CQDs based on ZIFs electrospun carbon fiber was constructed for the detection of malathion. Carbon quantum dots (CQDs) was obtained by pyrolysis of citric acid at high temperature. ZIFs electrospun carbon fiber (ENCF-67) prepared by electrospinning combined with high temperature calcination adsorbed Au NPs to obtain ENCF-67@Au. And the sensor of Nafion/ENCF-67@Au/CQDs/GCE was constructed by sequentially modified CQDs, ENCF-67@Au and Nafion on the electrode surfaces. ENCF-67@Au was used as the fixation material of CQDs and accelerator of system because ENCF-67 had the advantage of large specific surface area and porosity. Nafion/ENCF-67@Au/CQDs/GCE obtained sensitive and stable electrochemical luminescence signal in PBS containing S2O82-. The addition of malathion enhanced the ECL signal of the sensor with a linear increase in the range of 1.0 × 10-12 − 1.0 × 10-7 M and the limit of detection 3.3 × 10-13 M (S/N = 3). The sensor had good selectivity for malathion, which provided a simple and sensitive method for the detection of malathion in fruits and vegetables in real life and had potential applications.

Tris(2,2'-bipyridyl)ruthenium (II) complex as a universal reagent for the fabrication of heterogeneous electrochemiluminescence platforms and its recent analytical applications.

In recent years, electrochemiluminescence (ECL) has received enormous attention and has emerged as one of the most successful tools in the field of analytical science. Compared with homogeneous ECL, the heterogeneous (or solid-state) ECL has enhanced the rate of the electron transfer kinetics and offers rapid response time, which is highly beneficial in point-of-care and clinical applications. In ECL, the luminophore is the key element, which dictates the overall performance of the ECL-based sensors in various analytical applications. Tris(2,2'-bipyridyl)ruthenium (II) complex, Ru(bpy)32+, is a coordination compound, which is the gold-standard luminophore in ECL. It has played a key role in translating ECL from a "laboratory curiosity" to a commercial analytical instrument for diagnosis. The aim of the present review is to provide the principles of ECL and classical reaction mechanisms-particularly involving the heterogeneous Ru(bpy)32+/co-reactant ECL systems, as well as the fabrication methods and its importance over solution-phase Ru(bpy)32+ ECL. Then, we discussed the emerging technology in solid-state Ru(bpy)32+ ECL-sensing platforms and their recent potential analytical applications such as in immunoassay sensors, DNA sensors, aptasensors, bio-imaging, latent fingerprint detection, point-of-care testing, and detection of non-biomolecules. Finally, we also briefly cover the recent advances in solid-state Ru(bpy)32+ ECL coupled with the hyphenated techniques.

Impact of the metal core on the electrochemiluminescence of a pair of atomically precise Au20 nanocluster isomers

Although the electrochemiluminescence (ECL) of metal nanoclusters has been reported, revealing the correlation between structure and ECL at an atomic level is highly challenging. Here, we reported the impact of the metal core of Au20(SAdm)12(CHT)4 (Au20-AC for short; SAdm = 1-adamantanethiolate; CHT= cyclohexanethiol) and its isomer Au20(TBBT)16 (TBBT = 4-tert-butylthiophenol) on their solution-state and solid-state electrochemiluminescence. In self-annihilation ECL experiments, Au20-AC showed a strong cathodic ECL but a weak anodic ECL, while the ECL signal of Au20(TBBT)16 was weak and barely detectable. Density functional theory (DFT) calculations showed that the Au7 kernel of [Au20-AC]- is metastable, weakening its anodic ECL. Au20-AC in solution-state displayed an intense co-reactant ECL in the near-infrared region, which is 7 times higher than that of standard Ru(bpy)32+. The strongest solid-state ECL emissions of Au20-AC and Au20(TBBT)16 were at 860 and 770 nm, respectively — 15 nm red-shifted for Au20-AC and 20 nm blue-shifted for Au20(TBBT)16, compared to their corresponding solid-state photoluminescence (PL) emissions. This work shows that ECL is significantly affected by the subtle differences of the metal core, and offers a potential basis for sensing and immunoassay platforms based on atomically precise emissive metal nanoclusters.

Sensitive detection of H2O2 released from cancer cells with electrochemiluminescence sensor based on electrochemically prepared polypyrrole@Ce: Dy tungstate/polyluminol

The sensitive and rapid detection of H2O2 release from living cells has essential significance in the early diagnosis of many diseases. In this manuscript, a solid-state electrochemiluminescence (ECL) sensor was fabricated for ultrasensitive detection of Hydrogen peroxide (H2O2) with a comprehensive linear response in the ranges of 1 pmol/L to 10 μmol/L and a low detection limit of 0.198 pmol/L limit of quantification is 0.602 pmol/L. Briefly, The ECL sensor was developed based on electrodeposition layers of polypyrrole-Ce: Dy(WO4)3 nanocomposite for surface modification. Then poly Luminol was immobilized by electropolymerization on a glassy carbon electrode (GCE) surface as an ECL emitter. The properties of polypyrrole-Ce: Dy(WO4)3 nanocomposite and the modified electrode were evaluated using FE-SEM, Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and Atomic force microscopy (AFM) methods. Moreover, the ECL response of the PPy-Ce: Dy(WO4)3/Polyluminol electrode was applied to monitor the H2O2 level release from breast cancer cells (MCF-7). The ECL intensity was related to the logarithm of MCF-7 cell numbers, and the detection limit was 30 cells mol/L. Consequently, this ECL sensor was successfully applied to detect H2O2 released from living cancer cells with the advantages of sensitivity, reproducibility, rapid response, long-term stability, ease of operation, and low cost.

High-Performance Electrochemiluminescence of a Coordination-Driven J-Aggregate K-PTC MOF Regulated by Metal-Phenolic Nanoparticles for Biomarker Analysis.

The elimination of aggregation-caused quenching of polycyclic aromatic hydrocarbons by metal-ligand coordination is of immense scientific interest in solid-state electrochemiluminescence (ECL) sensing. Herein potassium ion (K+)-mediated J-aggregate K-PTC MOF (PTCA, perylene-3,4,9,10-tetracarboxylic) was synthesized and employed to formulate an ECL immunosensor for biomarker detection. The coordination-driven aggregates are arranged in an end-to-end side mode, which overcomes the aggregation-caused quenching related to PTCA concentration. Compared with PTCA, K-PTC MOF shows a more stable ECL emission with an unprecedented red shift to 718 nm and is equipped with ECL activity for analytical applications at a voltage of -1.1 V. Considering the requirements of accurate detection, metal-phenolic bioactive nanoparticles (MPNPs) were synthesized for the construction of a sandwich sensing platform to realize the steady-state regulation of ECL. As proof of applicability, a constructive experiment was carried out with neuron-specific enolase (NSE), a marker of small cell lung cancer (SCLC), as a targeted analyte. With optimal requirements, the configuration can provide a detection range of 10 pg/mL to 50 ng/mL and a detection limit of 7.4 pg/mL, accompanied by sufficient practical analytical performance. Collectively, this paradigm provides a deeper understanding of the ECL characteristics of coordination-driven J-aggregation and provides more possibilities for the development of ECL patterns based on luminescent metal-organic frameworks.

ZnO-Fe2O3 based electrochemiluminescence sensor for sensitive detection of malathion

Metal oxides containing iron and zinc (ZnO-Fe2O3) combined with ruthenium bipyridine [Ru(bpy)32+], graphene oxide (GO) and multi-walled carbon nanotube (MWNTs) were applied in the field of electrochemiluminescence (ECL). And a new solid-state ECL sensor for malathion determination by modifying ZnO-Fe2O3, Ru(bpy)32+, GO@MWNTs, Acetylcholinesterase (AchE) and Nafion on the electrode surface. The synthesized ZnO-Fe2O3 and GO@MWNTs with large specific surface area were used as carrier to anchor Ru(bpy)32+ and AchE, respectively. ZnO-Fe2O3 and GO@MWNTs can also be used as accelerators to promote electron transfer of the system. ZnO-Fe2O3 was also involved in the luminescence reaction, which increased the sensitivity of the system together with Ru(bpy)32+. Taking advantages of the electrocatalysis and electron transport capacity of ZnO-Fe2O3 and GO@MWNTs, the sensor obtained stable and amazing ECL response. The ECL response value decreased after malathion was introduced. In the range of 6.6 × 10−11 to 6.6 × 10−7 M, the decrease value (ΔI) was linearly related to the logarithm of malathion concentration, and the detection limit was 2.2 × 10−11 M. The method was simple and stable, and can be used to determine malathion in vegetable samples.

Solid-state electrochemiluminescence sensor based on the carbon fibers derived from ZIFs-containing electrospun fibers for chlorpyrifos detection

Carbon fiber containing zeolite imidazole framework-67 (ENCF-67) combined with graphene oxide (GO) and ruthenium bipyridine [Ru(bpy)32+] was first applied in the field of electrochemiluminescence (ECL). ENCF-67, GO@Ru(bpy)32+ and Nafion were successively modified on the electrode surface by layer-by-layer assembly method to fabricate a simple and sensitive solid-state ECL sensor. ENCF-67 prepared by electrostatic spinning combined with high temperature pyrolysis can not only fix Ru(bpy)32+, but also shorten the electron transport distance and promote the system electron transport due to the large specific surface area and porous structure. GO, which has a large specific surface area, worked with ENCF-67 to immobilize Ru(bpy)32+ and promote electron transfer in the system. The constructed sensor can obtain a significant ECL phenomenon under neutral condition. Chlorpyrifos can obviously quench the ECL signal of the constructed sensor, and the quenching value was associated with the concentration of chlorpyrifos. From 1.0 × 10–13 M to 1.0 × 10–6 M, the quenching value was positively correlated with the logarithm value of the concentration, which can be used for the quantitative detection of chlorpyrifos residues. This work not only expanded the application range of carbon fibers, but also provided an effective way for ECL signal amplification.

Electrospun nanofibers containing CdTe@ZnNi-MOF for electrochemiluminescent determination of chlorpyrifos.

Electrospun nanofibers containing CdTe@ZnNi-metal-organic frameworks (CdTe@ZnNi-MOF NFs) wereused for the first timein luminol-O2 electrochemiluminescence (ECL) system to construct ECL sensor for chlorpyrifos (CPF) detection. Firstly, CdTe@ZnNi-MOF NFs obtained by blending method was used tomodify the surface ofaglassy carbon electrode, and then, the proposed solid-state ECL sensor was constructed by dropping luminol onto the surface of nanofiber benefiting fromchitosan (CTS) viscosity. CdTe@ZnNi-MOF NFs with its large surface area and porosity can be used not only as luminol carrier but also as co-reaction promoter of the ECL system. The ECL sensor obtained satisfactory results in weakly alkaline solution under the synergistic action of CdTe@ZnNi-MOF NFs and luminol. The constructed ECL sensor can effectively detect CPF in the range 1.0 × 10-14-1.0 × 10-9M, and the detection limit was 6.23 × 10-17M (3σ/m). The constructed sensor was simple and sensitive, and can be used for the determination of CPF in vegetable samples. It not only broadened the application of MOFs in the field of ECL but also provided a new idea for expanding the application of theluminol-O2 system.

Functionalized Graphitic Carbon Nitride Nanomaterials for Electrochemiluminescent Detection of Cancer Cells

Biosensors capable of detecting cancer cell quantity is significant for cancer pathological investigation and prognosis. Herein, a facile electrochemiluminescent (ECL) biosensor is developed for cancer cell detection by comprehensively utilizing the features of functionalized graphitic carbon nitride (g-CN) nanomaterials like well film-forming capability and functionalization level tunability. The solid-state ECL biosensor is fabricated via a simple dropping-drying method by subsequent deposition of g-CN nanosheets/graphene oxide nanocomposites (CNNS/GO) as ECL emitter, folate functionalized g-CN quantum dots (FA-CNQDs) as cancer cell capture agent, and bull serum albumin (BSA) as blocker to prevent nonspecific binding on glassy carbon electrodes (GCEs). The strong and stable ECL emission of CNNS/GO along with the tunability of FA content in FA-CNQDs endow the ECL biosensor with competitive sensitivity, which is able to detect folate receptor-positive cancer cells (HepG2) in the concentration range of 102 − 104 cells ml−1 under optimal condition. Additionally, the proposed ECL biosensor shows high specificity, reproducibility and long-term stability as well as good reliability towards serum sample detection.