Solid-state Electrochemiluminescence Sensor 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

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.

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.

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.

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.

Solid-state electrochemiluminescence sensor based on zeolitic imidazolate framework-67 electrospinning nanofibers for chlorpyrifos detection.

A novel solid-state electrochemiluminescence (ECL) sensor for chlorpyrifos (CPF) detection was constructed based on zeolitic imidazolate framework-67 electrospinning nanofibers (ZIF-67 NFs). Silver nanoparticles (Ag NPs), ZIF-67 NFs, tris(2,2'-bipyridyl) ruthenium(II) [Ru(bpy)32+], and Nafion were successively deposited on the surface of the electrode. Ag NPs played a role in promoting electron transfer, and ZIF-67 NFs played a role in fixing Ru(bpy)32+ and promoting electron transfer due to its large specific surface area and porosity. Nafion formed a film on the outermost layer of the electrode to further improve the stability of the system. Therefore, the modified electrode showed stable and obvious ECL signal in PBS solution containing 10 μL 0.01M TprA (pH 8.0). CPF quenched the ECL signal of the system, and the quenching value was linear with the logarithm of CPF concentration in the range 1.0 × 10-13 to 1.0 × 10-6M. The detection limit was 3.3 × 10-14M (S/N = 3). In this study, ZIF-67 NFs were used as an ECL promoter for the first time, broadening the application range of ZIF-67 NFs.

Highly Active Electrochemiluminescence of Ruthenium Complex Co-assembled Chalcogenide Nanoclusters and the Application for Label-Free Detection of Alkaline Phosphatase.

Rational design of electrochemiluminescence (ECL) reagents is essential for the development of ECL biosensors with superior performances. In this work, the assembly of tris(1,10-phenanthroline)ruthenium(II) [Ru(phen)32+] and tetrahedral chalcogenide nanoclusters of [Cd32S14(SC6H5)38]2- in the formation of complex nanoclusters (CdS-Ru) was developed, in which Ru(phen)32+ was uniformly encapsulated and dispersed at a molecular level in the chalcogenide nanocluster via multiple noncovalent interactions. It was observed that the promoted ECL emission was realized by the charge transfer between the tetrahedral CdS nanocluster and Ru(phen)32+ by the formation of the assembly complex, which was elucidated by cyclic voltammetry curves, ECL-potential curves, and in situ dynamic ECL spectra. Taking advantages of the facile charge transfer in the open framework CdS-Ru, a high ECL efficiency has been achieved with remarkable stability. Moreover, a solid-state ECL sensor based on the CdS-Ru modified electrode was fabricated for label-free detection of alkaline phosphatase (ALP) activity with a detection limit as low as 0.35 U/L and superior reproducibility. This solid-state ECL sensor also displayed favorable selectivity among various interferences and was applied for ALP activity analysis in human serum samples. These results implicated the potential applications of CdS-Ru for sensitive ECL analysis in complicated reaction systems and enlightened the rational design for self-enhanced and highly efficient ECL materials.

A novel label-free solid-state electrochemiluminescence sensor based on the resonance energy transfer from Ru(bpy)32+ to GO for DNA hybridization detection

Based on electrochemiluminescence resonance energy transfer (ERET) from Ru(bpy)32+ to graphene oxide (GO), a novel label-free solid-state ECL sensor for sensitive detection of DNA was proposed. First, Ru(bpy)32+/AuNPs was successfully prepared by using a simple and green method and characterized by transmission electron microscopy (TEM), Energy Dispersive X-ray (EDX), and UV–vis spectroscopy. Then, the Ru(bpy)32+/AuNPs colloid was assembled on the gold electrode surface for solid-state ECL film which also later could be used to immobilize thiol-derivatized, single-stranded DNA (HS-ssDNA) via Au–S interactions. The stepwise modification procedure was characterized by cyclic voltammetry(CV), electrochemical impedance spectroscopy (EIS), probe approach curves (PAC) and ECL, respectively. The resulting modified electrode was tested as ECL biosensor for DNA detection. Upon addition of GO, the strong noncovalent interaction between HS-ssDNA and GO led to ECL quenching because of ERET. When in the presence of target ssDNA (t-ssDNA), the distance between the HS-ssDNA and GO increased, which significantly hindered the ERET and, thus, resulted in the restoration of ECL. The ECL intensity of the biosensor increased linearly with t-ssDNA concentration in the range of 50–1000pM, and the detection limit is 20pM. To the best of our knowledge, this is the first application of solid-state ERET from Ru(bpy)32+ to GO and opens new opportunities for sensitive detection of biorecognition events.

ZnO/CNT-COOHs based solid-state ECL sensor for tetracycline detection in fishpond water

A sensitive electrochemiluminescence (ECL) sensor in solid-state for the detection of tetracycline (TET), based on carboxylated carbon nanotubes modified ZnO (CNT-COOHs/ZnO), was developed in this research. The ZnO, which worked as luminophore here, was an environment-friendly material. Resulted from its tremendously specific surface area, the loading amount of CNT-COOHs increased. The CNT-COOHs played a role of catalyzer to enhance the ECL intensity of CNT-COOHs/ZnO modified glass carbon electrode (GCE) in triethanolamine (TEOA) contained electrolyte. After adding TET in the solution, the ECL intensity significantly quenched. The ΔECL intensity showed a good correlation to the concentration of TET in the range of 1.0 × 10–8–1.0 × 10–4 M and the detection limit achieved to 6.7 × 10–9 M within a response time of 1.0 min. Furthermore, the proposed CNT-COOHs/ZnO based ECL sensor was applied for the detection of TET in fishpond water and exhibited a good accuracy. We believe our system supplied a potential platform for the detection of TET in real world.

Electrochemiluminescence sensor for pentoxifylline detection using Au nanoclusters@graphene quantum dots as an amplified electrochemiluminescence luminophore

The Au nanoclusters@graphene quantum dots nanocomposite as an electrochemiluminescence (ECL) luminophore was synthesized through amide coupling reaction between Au nanoclusters (Au NCs) and graphene quantum dots (GQDs). The ECL intensity of the as-prepared Au NCs@GQDs was enhanced for 2.6-fold compared with that of Au NCs or 40-fold compared with that of GQDs, which was due to the ECL resonance energy transfer between GQDs as a donor and Au NCs as an acceptor, and excellent electrical conductivity of GQDs. In addition, the synergistic effect likewise improved stability of the ECL signal. A type of “signal-off” solid-state ECL sensor for detection of pentoxifylline was fabricated based on the selective quenching effect of pentoxifylline on the ECL signal of Au NCs@GQDs in alkaline medium. The sensor showed excellent sensitivity and wide linearity for pentoxifylline determination in the range from 7.0 × 10−7 to 1.2 × 10-4 mol/L with the detection limit of 9.0 × 10-8 mol/L (S/N = 3). The proposed method was successfully applied for pentoxifylline detection in pharmaceutical tablet with satisfactory results.

Electrochemiluminescence of metallated porous organic polymers

Electrochemiluminescence (ECL) has received considerable attention given its diverse applications, and the preparation of new luminophores remains interesting. Herein we report the synthesis of porous organic polymers containing bipyridine units that can coordinate ruthenium(II) and iridium(III) to form metallated porous organic polymers (MPOPs). We studied electrochemical behaviour and ECL of two MPOPs in the presence of tri-n-propylamine (TPrA) as the co-reactant. They generated ECL at 655 nm and 620 nm upon anodic polarization. The mechanism of ECL generation was investigated by dynamic ECL spooling spectroscopy. Considering MPOPs possess abundant pores, we believe they are potential in the fabrication of solid-state ECL sensors.

On-site determination of bisphenol A in river water by a novel solid-state electrochemiluminescence quenching sensor

Environmental contextBisphenol A is an endocrine disruptor, which may migrate and transfer to the environment where it presents a potential risk to the health of humans and animals. Herein, we demonstrate that electrospun nanofibers could be used to develop a highly efficient solid-state quenching sensor for on-site determination of bisphenol A in river water samples. The strategy has great potential for routine environmental analyses. AbstractA novel solid-state electrochemiluminescence (ECL) quenching sensor based on luminescent composite nanofibres for detection of bisphenol A (BPA) has been designed. Luminescent composite nanofibres of ruthenium(ii) tris(bipyridine) (Ru(bpy)32+)-doped core–shell Cu@Au alloy nanoparticles (Ru/Cu@Au) mixed with nylon 6 (PA6)–amino-functionalised multi-walled carbon nanotubes (MWCNTs), Ru/Cu@Au-MWCNTs-PA6, were successfully fabricated by a one-step electrospinning technique. The Ru/Cu@Au-MWCNTs-PA6 nanofibres, with a unique 3D nanostructure, large specific surface area and double Ru(bpy)32+-ECL signal amplification, exhibited excellent ECL photoelectric behaviours on a glassy carbon electrode. As a solid-state ECL sensor, the Ru/Cu@Au-MWCNTs-PA6 nanofibres can sensitively detect low concentrations of BPA by monitoring the BPA-dependent ECL intensity change. The detection limit for BPA is 10 pM, which is comparable or better than that in the reported assays. The sensor was successfully applied to on-site determination of BPA in river water samples obtained from eight different sampling sites with good recovery, ranging from 97.8 to 103.4%. The solid-state ECL sensor displayed wide-range linearity, high sensitivity and good stability, and has great potential in the field of environmental analyses.

Sensitive determination of bisphenol A using a novel solid-state electrochemiluminescence quenching sensor

ABSTRACTA novel solid-state electrochemiluminescence (ECL) quenching sensor based on the luminescent composite nanofibres for detection of bisphenol A (BPA) has been developed. The ruthenium(II) tris–(bipyridine) ()-doped silica nanoparticles (Ru@SiO2) mixed the nylon 6 (PA6)/carboxylated multiwalled carbon nanotubes (MWCNTs) luminescent composite nanofibres (Ru@SiO2–MWCNTs–PA6) were successfully fabricated by a one-step electrospinning technique. The Ru@SiO2–MWCNTs–PA6 nanofibres, with unique 3D nanostructure, large specific surface area and double -ECL signal amplification, exhibited excellent ECL photoelectric behaviours on glassy carbon electrode. As a solid-state ECL sensor, the Ru@SiO2–MWCNTs–PA6 nanofibres can sensitively detect low concentration BPA by monitoring the BPA-dependent ECL intensity change. The detection limit for BPA is 2.28 × 10−9 g L−1, which is comparable or better than that in the reported assays. The sensor was successfully applied to determine BPA leached from real plastic samples with good recovery, ranging from 97.5% to 103.4%. The solid-state ECL sensor displayed wide linear range, high sensitivity and good stability. It holds promise for the electrospun nanofibre-based ECL sensors which have a great potential for routine analyses.

A novel solid-state electrochemiluminescence sensor for detection of cytochrome c based on ceria nanoparticles decoratedwith reduced graphene oxide nanocomposite.

A novel ultrasensitive sensing system for the rapid detection of cytochrome c (CytC) was developed on the basis of an electrochemiluminescence (ECL) method. A nanocomposite biosensor was made of reduced graphene oxide decorated with cerium oxide/tris(2,2-bipyridyl)ruthenium(II)/chitosan (CeO2NPs-RGO/ Ru(bpy)3 (2+)/CHIT) and used for this purpose. The ECL signal was produced by an electrochemical interaction between Ru(bpy)3 (2+) and tripropyl amine (TPA) on the surface of the electrode. Addition of CytC to the solution decreases the ECL signal due to its affinity for TPA and inhibition of its reaction with Ru(bpy)3 (2+). The effects of the amount of CeO2NPs-RGO, Ru(bpy)3 (2+), TPA concentration as a co-reactant, and the pH of the electrolyte solution on the ECL signal intensity were studied and optimized. The results showed that the method was fast, reproducible, sensitive, and stable for the detection of CytC. The method has a linear range from 2.5nM to 2μM (R (2) = 0.995) with a detection limit of 0.7nM. Finally, the proposed biosensor was used for the determination of CytC in human serum samples with RSDs of 1.8-3.6%. The results demonstrate that this solid-state ECL quenching biosensor has high sensitivity, selectivity, and good stability. Graphical Abstract A novel solid-state electrochemiluminescence sensor for detection of cytochrome C based on Ceria Nanoparticles Decorated Reduced Graphene Oxide Nanocomposite.

Enhanced electrochemiluminescence of RuSi nanoparticles for ultrasensitive detection of ochratoxin A by energy transfer with CdTe quantum dots

This paper develops a new approach to enhance the electrochemiluminescence (ECL) emission of the Ru(bpy)32+-tripropyl amine (TPrA) system for ultrasensitive determination of ochratoxin A (OTA). Ru(bpy)32+-doped silica nanoparticles (RuSi NPs) act as ECL materials, which are immobilized on the surface of electrode by chitosan to fabricate a solid-state ECL sensor. CdTe quantum dots (QDs) can enhance the ECL emission of the Ru(bpy)32+-TPrA ECL system by energy transfer. This strategy can improve the sensitivity of the sensor. In this assay, we combine the ECL with molecular imprinting technique to improve the selectivity of this sensor. The template molecule could be eluted from the molecularly imprinted polymer (MIP), and the formed cavities could then selectively recognize the target. The cavities could also work as the tunnel for the transfer of coreactant TPrA to produce responsive signal. With the increase of the concentration of OTA in samples, more cavities were filled because of the rebinding of OTA to the MIP surface, resulting in a gradual decrease in ECL intensity. The results showed that the ECL decrease value depended linearly on the logarithm of the OTA concentration in the range from 1.00×10−5 to 11.13ngmL−1 with lower detection limit of 3.0fgmL−1 (S/N=3). This ECL sensor has also been applied to detect OTA concentration in the real samples with satisfied results, and the recoveries range from 85.1% to 107.9%.