Enhanced Electrochemiluminescence Intensity Research Articles

Ultrasensitive electrochemiluminescence biosensing from Cobalt single atom embedded high crystalline g-carbon nitride nanorod

Here, cobalt single-atom (Co SA) was introduced into the structure of the crystalline g-C3N4 nanorod (cry-CNN), which showed rapid electron transfer rate and excellent redox activity, thereby resulting in high electrochemiluminescence (ECL) emission. Compared to bulk g-C3N4, the cry-CNN had higher ECL intensity due to increasing the crystallinity to change the charge transport of electrons in the layer. Besides, benefiting from the unique electronic structure and catalytic activity of Co SA, the obtained Co SA@cry-CNN represented enhanced ECL intensity at a lower negative potential than that of cry-CNN, owing to the Co SA not only accelerated the electron transfer of the cry-CCN in heptazine cavity, but also promoted the co-reactive S2O82- to produce more active intermediate SO4•–. Interestingly, the experimental results showed that the ECL emission of Co SA@cry-CNN was about 23 times higher than that of BCN, and was 5 times higher than that of cry-CNN. Furthermore, using Co SA@cry-CNN as luminophore, a compact and efficient HCR-link-CHA(HLC) cascade amplification strategy was designed to construct a biosensor for detection of microRNA-222, which converted a certain amount of target to a DNA nanonet with plenty of quencher via N cycle of HCR and CHA reaction. The constructed biosensor had good monitoring performance and the limit of detection was as low as 40.0 amol/L. The proposed strategy integrated luminous structural adjustment and co-reaction efficiency improvement could be effectively extended to exploration of other novel ECL materials, and also provided new ideas for the early diagnosis of diseases.

Conjugated polymer-encapsulation-manipulated aggregation-induced electrochemiluminescence of tetraphenylethylene for sensitive malathion analysis

Tetraphenylethylene (TPE) and its derivatives with tunable structure and excellent photoelectric performance have aroused great concern in the field of electrochemiluminescence (ECL), but improving their ECL efficiency remains an enormous challenge in ECL bioanalysis. Herein, an encapsulation-manipulated aggregation-induced ECL (EM-AIECL) strategy was explored to effectively boost the ECL efficiency of TPE. Large π-conjugated polymer poly[2,5-dioctyl-1,4-phenylene] (PDP) was creatively developed as encapsulation matrix to envelop TPE molecules via hydrophobic interactions. The resulting complex TPE@PDP nanoparticles (NPs) not only restricted the molecule motion of TPE due to space limitation, but also inhibited the aggregation-caused quenching effect caused by TPE crystals featuring dense aggregation structure. Furthermore, the robust electronic coupling between PDP and TPE aggregates enabled superior charge transport within TPE@PDP NPs, thus yielding strong AIECL. As compared to TPE crystals, TPE@PDP NPs showcased 3.87-fold enhancement of ECL intensity. Impressively, TPE@PDP NPs coupled a three-dimensional DNA walker-assisted multiple rolling circle amplification strategy to construct an ECL sensing platform for malathion analysis, and a wide linear range of 5.0 fM ∼ 0.5 μM and low limit of detection of 0.9 fM were obtained. EM-AIECL strategy provides a new idea for designing organic AIECL luminophors, and opens an avenue for detecting pesticides specifically and sensitively.

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.

Nickel Single-Atom Catalyst Boosts Electrochemiluminescence of Graphitic Carbon Nitride for Sensitive Detection of HBV DNA.

Owing to excellent catalytic activity, single-atom catalysts (SACs) have recently attracted considerable research interest in the electrochemiluminescence (ECL) field. However, the applications of SACs are mostly limited to conventional luminol ECL system. Hence, it is necessary to explore the application of SACs in more ECL systems. In this work, nickel single-atom catalysts (Ni SACs) were successfully applied in the graphitic carbon nitride (g-C3N4)-H2O2 ECL system to significantly enhance its cathodic emission. Notably, g-C3N4 acted not only as an ECL luminophore but also as a support to anchor Ni SACs. Ni SACs can significantly activate H2O2 to produce abundant OH• radicals for enhancing the cathodic ECL emission of g-C3N4. Ni SACs-anchored g-C3N4 (Ni SACs@g-C3N4) had a 10-fold enhanced ECL intensity as compared to g-C3N4. Finally, the Ni SACs@g-C3N4-H2O2 ECL system was developed to detect hepatitis B virus (HBV) DNA by incorporating an entropy-driven DNA walking machine-assisted CRISPR-Cas12a amplification strategy. The constructed biosensor exhibited excellent detection performance for HBV DNA with a limit of detection as low as 17 aM. This work puts forward a new idea for enhancing the cathodic ECL of g-C3N4-H2O2 and expands the application of SACs in the ECL system.

A sandwich electrochemiluminescence immunoassay based on 1T-MoS2@dual MOFs for detecting CA153

A “signal-on” electrochemiluminescence (ECL) immunosensor has been proposed for detecting carbohydrate antigen 153 (CA153) based on the dual MOFs sandwich strategy. The conductive and porous substrate consisting of 1T-MoS2 and two-dimensional conductive metal-organic framework (MOF, Ni-HAB) was anchored onto the glassy carbon electrode (GCE) to label the capture antibody (Ab1), and the luminescence-functionalized MOF (Ru(bpy)32+@UiO-66-NH2) was utilized to immobilize the detection second antibody (Ab2) to construct a “signal-on” responsive sandwich-type electrochemiluminescence immunoassay. Meanwhile, tripropylamine (TPA) acts as the co-reactant and provides a luminescence system for Ru(bpy)32+@UiO-66-NH2. The luminescence-functionalized MOFs showed excellent ECL activity owing to the tunable structure of MOFs. The remarkable enhancement in ECL intensity was obtained by the immunoreaction of antigen and antibody. Under the optimized conditions, the biosensor exhibited a detection limit of 0.0001 U mL−1 (S/N = 3) with a wide range from 0.001 to 50 U mL−1. The proposed ECL immunosensor was applicable for detecting human serum samples with a recovery of 99.83 ∼ 101 % (RSD < 5 %). This work demonstrates that the advantage of multifunctional MOFs could be applied to construct highly selective ECL immunosensor, and it may facilitate the diagnosis of breast cancer in clinics.

Facile electrochemiluminescence sensing platform based on Gd2O3:Eu3+ nanocrystals for organophosphorus pesticides detection in vegetable samples

In this work, europium ion-doped gadolinium trioxide nanocrystals (Gd2O3:Eu3+ NCs) were successfully synthesized and applied to construct an electrochemiluminescence (ECL) sensor. Compared with pure Gd2O3, the doping of Eu3+ ions caused enhanced ECL intensity and more stable signals. Based on the excellent ECL performance of Gd2O3:Eu3+ NCs, we constructed a new ECL sensing platform for the detection of organophosphorus pesticides (OPs). The ECL sensor showed a good linear relationship in the concentration range of 1 nM to 1 pM, with a limit of detection of 0.12 pM (S/N = 3) for dichlorvos (DDVP). In addition, the constructed ECL sensor was applied for the detection of DDVP in vegetable samples, and good recoveries were obtained. The results indicated that the ECL sensor exhibited fantastic performance properties and had good application prospects in OPs detection.

A smartphone-assisted electrochemiluminescent detection of miRNA-21 in situ using Ru(bpy)32+@MOF

We have proposed a signal dual-amplification electrochemiluminescence (ECL) strategy based on tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) as chromophores confined with three-dimensional (3D) zinc oxalate metal−organic frameworks (Ru(bpy)32+@MOFs) for the detection of miRNA-21. The three-dimensional chromophore connectivity in zinc oxalate MOFs provided a network among Ru(bpy)32+ units, shielding the chromophores from solvent molecules and resulting in high Ru(II) complex emission efficiency. Additionally, we discovered that magnetic beads (MBs) used as carrier for enriched signals contribute to enhanced ECL intensity of the chromophore. To evaluate its clinical application, we applied this method to determine the concentration of miRNA-21 solutions ranging from 1.56 to 100 nM, obtaining a calibration curve of ECL intensity versus logarithm of concentration (logC) of miRNA-21 with a high correlation coefficient. This work demonstrates the construction of a signal amplification strategy ECL biosensor for miRNA using Ru(bpy)32+@MOF systems and its application in ECL detection for analyte methodology.

Aggregation-induced electrochemiluminescence enhancement of Ag-MOG for amyloid β 42 sensing

This study aimed to introduce an immunosensor for measuring amyloid β 42 (Aβ42) levels by aggregation-induced enhanced electrochemiluminescence (ECL). Metal–organic gels (MOGs) are novel soft materials with advantages such as high gel stability, good light-emitting properties, and easy preparation. This study used silver nanoparticle metal–organic gel (Ag-MOG) as a substrate to connect Aβ42-Ab2 and the cathodoluminescent probe. Potassium persulfate was used as a co-reactant that could emit a high ECL signal. CuS@Au had the benefits of a relatively large surface area with excellent carrier function; therefore, it was used as a substrate to load a large amount of Aβ42-Ab1, significantly improving the immunosensor sensitivity. The ECL intensity of Aβ42 was linear in the range of 0.01 pg/mL to 250 ng/mL with a detection limit of 2.2 fg/mL (S/N = 3) under optimized detection conditions. This ECL immunosensor has been successfully applied to detect Aβ42 in human serum with the advantages of excellent stability and high selectivity. This method not only expands the potential applications of ECL immunosensors based on biological testing and clinical diagnosis but also provides a viable approach to basic clinical testing.

A new sandwich-type electrochemiluminescence sensor based on HPSNs-NH2@Au NPs and AuPdPt NPs for determination of α(2,3)-sial-Gs.

A novel sandwich-type "on-off" electrochemiluminescence (ECL) biosensor for the determination of α(2,3)-sial-Gs was designed. Specifically, amino-functionalized porous silica nanoparticles (HPSNs-NH2) were first prepared and then decorated with gold nanoparticles (Au NPs) to form HPSNs-NH2@Au NP nanocomposite, which exhibited a strong ability to enhance ECL intensity with K2S2O8 as co-reactant (signal-on) and could immobilize the target-specific binding molecules of maackia amurensis lectin (MAL). Additionally, AuPdPt trimetallic nanoparticles were prepared to serve as a quenched ECL signal indicator (signal-off) with the ability of capturing the target non-specific binding molecules of 3-aminophenylboronic acid (APBA) to form a signal label. The sandwich-type ECL biosensor was constructed based on the structure of MAL-α(2,3)-sial-Gs-APBA and achieved a determination toward α(2,3)-sial-Gs with a wide linear range from 1 fg mL-1 to 10 ng mL-1 and a low detection limit of 0.5 fg mL-1. Furthermore, the proposed ECL biosensor showed satisfactory selectivity, stability, and reproducibility for α(2,3)-sial-Gs determination.

Fullerene-promoted organic-inorganic hybrid electrochemiluminescence biosensor for sensitive detection of concanavalin A

A fullerene-promoted organic-inorganic hybrid electrochemiluminescence (ECL) biosensor was proposed for sensitive detecting concanavalin A (ConA). Here, platinum-modified inorganic TiO2 (Pt-TiO2) promotes charge transfer to enhance ECL intensity of organic luminescent probe—ammonolysis product of PTCDA (PTC). Fullerene interacts with K2S2O8 co-reagent to produce more SO4•− free radicals, and its large specific-surface-area and electrophilic nature are beneficial to loading more luminescent PTC. The glucose oxidase (GOx) is chosen for specific recognition of ConA through a biospecific interaction. The constructed ECL biosensor shows a wide detection range of 1 × 10−4–1 × 103 ng mL−1 with a low detection limit (LOD) of 1.8 × 10−5 ng mL−1, as well as high stability, reproducibility, and detection capability of actual serum. This work provides a promising organic-inorganic hybrid biosensor platform for early biotherapy and clinical diagnosis.

Development of a gliadin immunosensor incorporating gold nanourchin, molybdenum disulfide, titanium dioxide, and Nafion for enhanced electrochemiluminescence

Gluten contamination is a constant risk for people with celiac disease (CD), necessitating the development of specific and ultra-sensitive methods for detecting Gliadin. Here, we report the first use of a screen-printed gold electrode (SPGE) modified with a novel nanocomposite of gold nanourchin/molybdenum disulfide/titanium dioxide (AuNU/MoS2/TiO2) in Nafion to detect Gliadin using electrochemiluminescence (ECL). The nanocomposite enhanced ECL intensity by 5.6 times compared with the bare SPGE. The immunosensor had a linear detection range of 0.005–500 pg/mL, with a low limit of detection (LOD) of 0.005 pg/mL, the lowest among other Gliadin immunosensors. The immunosensor exhibited high selectivity, reproducibility, and stability, and demonstrated excellent recoveries (98.0%–104.9%) of Gliadin from real samples. The proposed immunosensor has the potential to provide a rapid and accurate gluten detection tool for the food industry, and to help protect CD patients against gluten exposure.

Visual Electrochemiluminescence Biosensor Chip Based on Distance Readout for Deoxynivalenol Detection

Visual electrochemiluminescence (ECL) biosensors do not need complex instruments or well-trained operators, which is regarded as an ideal choice for portable and low-cost detection. But traditional visual ECL biosensors are based on the change in ECL intensity, which is easily affected by environmental factors and signal acquisition processes. In this work, a visual ECL biosensor chip based on distance readout has been developed for the first time. The chip is composed of a square detection region and a visual channel region, which are modified with graphene oxide (GO) and gold nanoparticles (AuNPs)@Ti3C2 nanocomposites, respectively. Target molecules can release aptamers adsorbed on the GO surface of the detection region and further change the electrode potential of the visual channel region, which can determine the length of the long channel that generates visible ECL signals. The application of AuNPs@Ti3C2 nanocomposites can effectively enhance ECL intensity by six times. Through the unique design of the sensor chip, quantification detection can be achieved based on the length change instead of the traditional intensity change. This visual ECL sensor is successfully applied for deoxynivalenol toxin detection in actual samples, demonstrating that the introduction of the distance readout strategy into ECL sensing has a good prospect in on-site testing.

Ordered heterogeneity in dual-ligand MOF to enable high electrochemiluminescence efficiency for bioassay with DNA triangular prism as signal switch

Herein, the microRNA-141 electrochemiluminescence (ECL) bioassay was developed using the dual-ligand metal-organic framework (d-MOF) with ordered heterogeneity, which simultaneously contained the luminophore ligands (1,1,2,2-tetra(4-carboxylbiphenyl)ethylene, denoted as TCBPE) and the coreactant ligands (1,4-diazabicyclo[2.2.2]octane, denoted as DN2H2). The resultant d-MOF revealed significantly enhanced ECL intensity without any exogenous coreactants, which was 3.53 times higher in comparison with that of single-ligand MOF (only TCBPE as ligands) even with the addition of exogenous DN2H2. Thanks to the ordered heterogeneity in d-MOF, the intramolecular rotation of TCBPE was restricted via oriented coordination and the spatial location of DN2H2 was reasonably arranged due to the framework structure, which could not only enhance the excitation efficiency but also improve the electron-transfer efficiency based on the synergistic enhancement effect between structures and compositions in micro/nano confined space. Based on this, the proposed biosensor employed a novel DNA triangular prism (DNA TP) as signal switch to detect microRNA-141, achieving the low detection limit at the level of 22.9 aM and a broad linear ranging from 100 aM to 100 pM. The precise design of the ordered d-MOFs by co-assembling the luminophore and coreactant ligands holds a promise strategy to achieve ECL MOFs and construct the ECL biosensors in diagnostic analysis.

Determination of trichlorfon using a molecularly imprinted electrochemiluminescence sensor on multi-walled carbon nanotubes decorated with silver nanoparticles.

Considering the limitations associated with existing methods for the detection of trace amounts of trichlorfon, this paper proposes a novel molecularly imprinted electrochemiluminescence (ECL) sensor for the detection of trichlorfon by utilizing the double enhancement effect of trichlorfon and Ag nanoparticles supported by multi-walled carbon nanotubes (MWCNTs/Ag NPs) in a luminol-H2O2 ECL system. Here, trichlorfon was electropolymerized on the surface of the MWCNT/Ag NP-modified gold nanoelectrode with o-phenylenediamine to prepare the molecularly imprinted polymer-based sensor. After eluting the trichlorfon, imprinted holes for the identification of trichlorfon were retained on the sensor, which were used as signal switches to obtain different ECL intensities through the adsorption of different concentrations of trichlorfon. The ECL signal of the sensitized luminol-H2O2 was doubly enhanced by the MWCNTs/Ag and trichlorfon, improving the sensitivity of the sensor. The trichlorfon concentration was positively correlated with the enhanced ECL intensity of the sensor in the range 5.0 × 10-8-5.0 × 10-11mol L-1, and the detection limit of trichlorfon was 3.9 × 10-12mol L-1. Moreover, the proposed sensor was successfully applied to the detection of trichlorfon residues in real samples, and the recovery ranged between 91.8 and 109%. A molecularly imprinted electrochemiluminescence sensor for trichlorfon detection by utilizing the double enhancement effect of trichlorfon and Ag nanoparticles supported by multi-walled carbon nanotubes in a luminol-H2O2 ECL system. The dual enhancement of the ECL signal improved the sensitivity of the sensor.

MicroRNA-21 electrochemiluminescence biosensor based on Co-MOF-N-(4-aminobutyl)-N-ethylisoluminol/Ti3C2Tx composite and duplex-specific nuclease-assisted signal amplification.

Anovel electrochemiluminescence (ECL) biosensor for the determination of microRNA-21 (miRNA-21)was developed, based on a hybrid luminescent Co-MOF-ABEI/Ti3C2Tx composite as an ECL luminophore combined with a duplex-specific nuclease (DSN)-assisted signal amplification strategy. The synthesized Co-MOF-ABEI/Ti3C2Tx composite carrying N-(4-aminobutyl)-N-ethylisoluminol (ABEI) exhibited strong and stable ECL in the presence of reactive oxygen species (ROS). The ECL biosensor was fabricated by adsorbing Co-MOF-ABEI/Ti3C2Tx onto a glassy carbon electrode and covalently coupling the probe DNA onto the surface of the Co-MOF-ABEI/Ti3C2Tx-modified electrode. In the presence of the target miRNA-21, the DSN selectively cleaved the complementary DNA section (S1) to miRNA-21, resulting in the release of the transduction section (S2) and the reuse of miRNA-21 in the subsequent amplification cycle. The interaction of the stem-loop structure of the probe DNA with the Co-MOF-ABEI/Ti3C2Tx-modified glassy carbon electrode with S2 strands led to the opening of the annular part of the probe DNA. Then, the opened guanine (G)-rich sequences of probe DNA were exposed and folded into a hemin/G-quadruplex DNAzyme in the presence of hemin. Thecatalysis of H2O2 to ROS by the hemin/G-quadruplex DNAzyme significantly enhanced ECL intensity, and this intensity was logarithmically proportional to the concentration of target miRNA-21 between 0.00001 and 10nM, having a limit of detection of 3.7 fM. Thedesigned ECL biosensor can detect miRNA-21 extracted from HeLa cells, indicating its promising application in clinical diagnosis and disease prognosis analysis.

Intrareticular charge transfer regulated electrochemiluminescence of donor\u2013acceptor covalent organic frameworks

The control of charge transfer between radical anions and cations is a promising way for decoding the emission mechanism in electrochemiluminescence (ECL) systems. Herein, a type of donor-acceptor (D-A) covalent organic framework (COF) with triphenylamine and triazine units is designed as a highly efficient ECL emitter with tunable intrareticular charge transfer (IRCT). The D-A COF demonstrates 123 folds enhancement in ECL intensity compared with its benzene-based COF with small D-A contrast. Further, the COF’s crystallinity- and protonation-modulated ECL behaviors confirm ECL dependence on intrareticular charge transfer between donor and acceptor units, which is rationalized by density functional theory. Significantly, dual-peaked ECL patterns of COFs are achieved through an IRCT mediated competitive oxidation mechanism: the coreactant-mediated oxidation at lower potential and the direct oxidation at higher potential. This work provides a new fundamental and approach to improve the ECL efficiency for designing next-generation ECL devices.

Carbon dots and gold nanoparticles doped metal-organic frameworks as high-efficiency ECL emitters for monitoring of cell apoptosis

Synthesis of highly efficient, cost-effective, Easy labeling electrochemiluminescence (ECL) luminescent materials is attractive in developing highly sensitive ECL sensors for many applications such as clinical diagnostics, biosecurity, and environmental monitoring. Herein, by doping carbon dots (CDots) and gold nanoparticles (AuNPs) into zeolitic imidazolate framework (ZIF-8), novel high-efficiency ECL emitters CDots@ZIF-8/AuNPs nanocomposites were prepared. Our experiment indicated that ZIF-8 in the nanocomposites not only act as carrier for ECL labels, but as an ECL accelerator to convert the CDots to CDots•–, causing the enhanced ECL intensity of CDots in K2S2O8 solution. AuNPs, which have excellent conductivity, were formed in the pores of ZIF-8 to further enhance the ECL signals. As a result, the nanocomposites showed a final about 7-fold ECL intensity as compared to the pure CDots. AuNPs in the nanocomposites could also provide a platform for effective attaching the biomolecular, making the nanocomposites ideally suited for building biosensor. As a proof of concept, the prepared CDots@ZIF-8/AuNPs was successfully applied in the rapid and simple ECL monitoring of caspase-3 activity during cell apoptosis, which gives impetus to the design of new ECL luminescent materials with ultimate applications in highly sensitive bioanalysis.

Bioinspired N-C coated ZnO based electrochemiluminescence sensor for dopamine screening from neuroblastoma patient

• An electrochemiluminescence sensor for dopamine (DA) has been constructed by using ZnO nanoparticles coated with bioinspired N rich C (NC) dots. • The designed sensor provides highly sensitive and selective monitoring of DA. • The limit of detection and linear range of designed electrode was 4.2 nM and 5–300 µM, respectively. • The developed sensor shows reliability in monitoring DA from blood of neuroblastoma patient. Precise monitoring of dopamine (DA) helps in diagnosing and treatment of various neurological disorders such as Dementia, Parkinson's and Alzheimer's diseases etc. Thus, herein. we reported a novel sensing platform based on bioinspired N rich C (NC) coated ZnO (NC@ZnO) for the control monitoring of DA by electrochemiluminescence (ECL) method. The synthesized NC@ZnO material characterized through SEM, TEM, XPS and Raman spectroscopy. Our results shows that a cathodic ECL signal is generated at the surface of ZnO when exposed to K 2 S 2 O 8 co-reactant, and interestingly the intensity increases by more than 200 times upon incorporation with bioinspired NC. Thus, the developed NC@ZnO system with enhanced ECL intensity was further successfully employed to monitor DA. Under optimal conditions, the ECL sensors shows a good linear range (5–300 µM) with excellent limit of detection (LOD) value of 4.2 nM (based on 3σ). The designed sensor also shows promising selective efficacy even in the presence of co-existing active species such as ascorbic acid (AA), uric acid (UA), glucose (Glu), L. Cysteine i.e., and reliability in terms of precise monitoring of DA from blood of neuroblastoma patient.

A Highly Sensitive Electrochemiluminescence Spermine Biosensor Based on Au−Ag Bimetallic Nanoclusters

AbstractIn this study, we found that spermine (SPM) could enhance electrochemiluminescence (ECL) intensity of Au−Ag bimetallic nanoclusters (Au−Ag BNCs) with triethylamine (TEA) as a co‐reactant. An ECL sensor was fabricated to detect SPM, which contained Au−Ag BNCs as ECL emitters and conductive hydrogel containing polyaniline‐amino trimethylene phosphonic acid (PANI‐ATMP) as an immobilizing matrix. The increased ECL intensity of SPM was linear with the logarithm of concentrations of SPM in the range of 1 pM to 10 μM with high selectivity, excellent stability, and the limit of detection is 0.11 pM (S/N=3). This sensor realized the detection of SPM in urine samples, which was fast and economic, possessing potential applications for SPM detection in clinical and bioanalysis.

Rational Design of Electrochemiluminescent Devices.

Electrochemiluminescence (ECL) is a light-emitting process which combines the intriguing merits of both electrochemical and chemiluminescent methods. It is an extensively used method especially in clinical analysis and biological research due to its high sensitivity, wide dynamic range, and good reliability. ECL devices are critical for the development and applications of ECL. Much effort has been expended to improve the sensitivity, portability, affordability, and throughput of new ECL devices, which allow ECL to adapt broad usage scenarios.In this Account, we summarize our efforts on the recent development of ECL devices including new electrodes, ECL devices based on a wireless power transfer (WPT) technique, and novel bipolar electrochemistry. As the essential components in the ECL devices, electrodes play an important role in ECL detection. We have significantly improved the sensitivity of luminol ECL detection of H2O2 by using a stainless steel electrode. By using semiconductor materials (e.g., silicon and BiVO4), we have exploited photoinduced ECL to generate intense emission at much lower potentials upon illumination. For convenience, portability, and disposability, ECL devices based on cheap WPT devices have been designed. A small diode has been employed to rectify alternating current into direct current to dramatically enhance ECL intensity, enabling sensitive ECL detection using a smart phone as a detector. Finally, we have developed several ECL devices based on bipolar electrochemistry in view of the convenience of multiplex ECL sensing using a bipolar electrode (BPE). On the basis of the wireless feature of BPE, we have employed movable BPEs (e.g., BPE swimmers and magnetic rotating BPE) for deep exploration of the motional and ECL properties of dynamic BPE systems. To make full use of the ECL solution, we have dispersed numerous micro-/nano-BPEs in solution to produce intense 3D ECL in the entire solution, instead of 2D ECL in conventional ECL devices. In addition, the interference of ECL noise from driving electrodes was minimized by introducing the stainless steel with a passivation layer as the driving electrode. To eliminate the need for the fabrication of electrode arrays and the interference from the driving electrode and to decrease the applied voltage, we develop a new-type BPE device consisting of a single-electrode electrochemical system (SEES) based on a resistance-induced potential difference. The SEES is fabricated easily by attaching a multiperforated plate to a single film electrode. It enables the simultaneous detection of many samples and analytes using only a single film electrode (e.g., screen-printed electrode) instead of electrode arrays. It is of great potential in clinical analysis especially for multiple-biomarker detection, drug screening, and biological studies. Looking forward, we believe that more ECL devices and related ECL materials and detection methods will be developed for a wide range of applications, such as in vitro diagnosis, point-of-care testing, high-throughput analysis, drug screening, biological study, and mechanism investigation.