Electrochemiluminescence Aptasensor Research Articles

Integrating All-rounder TiO2 Accelerated Electrochemiluminescence with Dual-Quenching PDA@COF Probes for Sensitive Quantification and Protein Profiling of Tumorous Exosomes.

Exosomes have been perceived as promising biomarkers for noninvasive cancer diagnosis and treatment monitoring. However, the sensitive and accurate quantification and phenotyping of exosomes remains challenging. Herein, a versatile electrochemiluminescence (ECL) aptasensor was proposed for the sensitive analysis of tumorous exosomes. Specifically, a ternary nanohybrid (Ru-HAuTiO2), by covalently linking ECL luminophore Ru(dcbpy)32+ with gold nanoparticles (AuNPs)-decorated hollow urchin-like TiO2 (HTiO2), was ingeniously designed as a highly luminescent and self-enhanced ECL nanoemitter. Notably, the porous HTiO2 played an "all-rounder" role, including the carrier for ECL luminophores and AuNPs, coreaction accelerator, and specific exosome capturing scaffold through Ti-phosphate coordination interaction. On the other hand, a polydopamine modified covalent organic framework (PDA@COF) was employed as a quencher to remarkably attenuate the ECL of Ru-HAuTiO2 through a dual-quenching mechanism, and further labeled with a specific aptamer (Apt) of exosomal surface protein. Based on forming a Ru-HAuTiO2/exosome/Apt-PDA@COF sandwich structure on the electrode, a "signal on-off" ECL platform for tumorous exosomes was constructed, realizing sensitive detection within the range of 3.1 × 103 particles/mL to 1 × 108 particles/mL and a low limit of detection of 1.41 × 103 particles/mL, achieving phenotypic profiling of surface proteins on different tumorous exosomes. This work provides a promising alternative method for the detection and analysis of exosomes.

Aptamer-Triggered Nucleic Acid Amplification Strategy for the Electrochemiluminescence Detection of Perfluorooctanoic Acid.

Per- and polyfluoroalkyl substances (PFASs) are a class of persistent micropollutants. Due to their chemical stability and bioaccumulation, concentrations of PFASs in environmental media, even at ultratrace levels, pose significant environmental and health risks. However, currently reported detection methods lack an effective signal amplification strategy, and the detection sensitivity is limited, which can not meet the requirements of ultratrace detection. Herein, a groundbreaking aptamer-recognition-driven nucleic acid strategy was developed to significantly amplify the detection signal of perfluorooctanoic acid (PFOA). Furthermore, step pulse (SP) was used instead of cyclic voltammetry (CV) as an electrochemical excitation method to modulate the low electrochemiluminescence (ECL) triggering potential of poly [9,9-bis (3'-(N, N-dimethylamino) propyl) -2,7-fluorene]-alt-2,7-(9,9-dioctylfluorene)] (PFN) nanoparticles (NPs) so that a strong signal of +0.80 V was emitted without any exogenous coreactants. PFN NPs coupled rolling circle amplification-assisted PAM-free CRISPR/Cas12a system to construct an ultrasensitive ECL aptasensor for PFOA detection and the limit of detection was as low as 1.97 × 10-15 M. This ECL system integrated the advantages of no exogenous coreactants, low trigger potential, and nucleic acid amplification strategy and provided an ultrasensitive method for monitoring trace PFOA in the real water sample.

Ultralow Potential Cathodic Electrochemiluminescence Aptasensor for Detection of Kanamycin Using Copper Nanoribbons as Coreaction Accelerator.

An ultralow cathodic potential electrochemiluminescence (ECL) aptasensor was designed, employing DNA nanoribbon template self-assembly copper nanoclusters (DNR-CuNCs) as a novel coreaction accelerator within the luminol-H2O2 system for the sensitive detection of kanamycin (KANA). Mechanistic investigations revealed that the DNR-CuNCs preferred to generate highly active hydroxyl radicals by facilitating the reduction of the coreactant H2O2 under neutral pH conditions, consequently enhancing cathodic luminescence. By the strong π-π stacking effect of KANA aptamer and graphene as a signal modulation switch, DNR-CuNCs were displaced from the electrode surface due to the affinity of KANA and its aptamer, resulting in the inhibition of the luminol-H2O2 system and a decrease in the ECL signal. Under optimal experiments, the aptasensor demonstrated exceptional sensitivity in detecting KANA within the concentration range from 1 × 10-2 to 5 × 105 pg/mL, with the detection limit as low as 0.18 fg/mL. This innovative strategy provided a novel approach to designing effective ECL emitters for monitoring food safety.

A self-enhanced electrochemiluminescence aptasensor Zr-porphyrin modified with polyamidoamine for sensitive detection of lincomycin

A self-enhanced electrochemiluminescence aptasensor Zr-porphyrin modified with polyamidoamine for sensitive detection of lincomycin

Dual-Mechanism Quenching Electrochemiluminescence System by Coupling Energy Transfer with Electron Transfer for Sensitive Competitive Aptamer-Based Detection of Furanyl Fentanyl in Food.

Resonance energy transfer (RET) quenching is significantly important for developing electrochemiluminescence (ECL) sensors, but RET platforms face challenges like interference from other fluorescent substances and reliance on energy transfer efficiency. This study used Zn-PTC, formed by zinc ions coordinated with perylene-3,4,9,10-tetracarboxylate, as a dual-mechanism quencher to reduce the ECL intensity of carbon nitride nanosheets (Tg-CNNSs). Co3O4/NiCo2O4 acts as a coreaction promoter, enhancing and stabilizing the luminescence of Tg-CNNSs. Zn-PTC absorbs energy from Tg-CNNSs, altering the fluorescence lifetime to confirm energy transfer, while energy-level matching demonstrates electron transfer. By leveraging both RET and electron transfer mechanisms, the designed ECL aptasensor significantly reduces signal fluctuations that may arise from a single mechanism, resulting in more stable and reliable detection outcomes. The ECL aptasensor designed for furanyl fentanyl (FUF) detection shows excellent performance with a detection limit of 5.7 × 10-15 g/L, offering new pathways for detecting FUF and other small molecules.

Automated ECL Aptasensing Platform from an Intrarticular Radical Annihilation Route for Distinguishing Glioma Stages.

Nowadays, continuous efforts have been devoted to designing stable and high-efficiency electrochemiluminescence (ECL) emitters as alternatives for tris(2,2'-bipyridine)-ruthenium(II) (Ru(bpy)32+) in medical research. Herein, a novel ECL emitter was obtained by coordinating crystalline covalent triazinyl frameworks (cCTFs) with Ru2+ (termed Ru-cCTFs), which exhibited strong ECL emission by the ligand to metal charge transfer (LMCT) route. After its integration with 4-mercaptopyridine (SH-Py), the resultant SH-Py-Ru-cCTFs achieved 2.3-fold enhancement in the ECL efficiency by employing Ru(bpy)32+ as a standard, which involved a dynamic "intrarticular radical annihilation" ECL pathway. On such foundation, an automated ECL (A-ECL) aptasensor was constructed with an "on-off-on" model and magnetic separation upon linkage of the SH-Py-Ru-cCTFs with streptavidin (SA) magnetic beads (MBs). This automatic assay of miRNA-182 showed a wider linear range from 1.0 to 100.0 fM with a correlation coefficient (R2) of 0.994, a lower limit of detection (LOD) down to 0.28 fM, and faster operation within 41 min. Impressively, this bioassay facilely distinguished the stages of glioma disease from clinical blood samples with high accuracy. Hence, this research sheds light on how to develop advanced ECL luminophores and an automatic method, showing substantial insights into pathogenesis research of gliomas.

Novel electrochemiluminescence platform utilizing AuNPs@Uio-66-NH2 bridged luminescent substrates and aptamers for the detection of pesticide residues in Chinese herbal medicines

A large number of Chinese herbal medicines (CHMs) are included in daily recipes, but their pesticide residues have aroused more and more concerns. In this paper, an electrochemiluminescence aptasensor was constructed for the trace detection of acetamiprid (ACE) in Angelica sinensis and Lycium barbarum. Possessing a large specific surface area, UiO-66 was modified with amino groups to improve biocompatibility, and the addition of AuNPs allowed UiO-66-NH2 to catalyze the formation of excited states of luminescent molecules (TPrA⁎; Ru(bpy)32+⁎), and AuNPs@UiO-66-NH2 was used to bridge the aptamer (Au–S) and luminescent substrate (peptide bond). The conventional luminescent reagent Ru(bpy)32+ was doped with multi-walled carbon nanotubes (MWCNTs) to obtain a more powerful and stable light signal. After optimizing the experimental parameters, the aptasensor could give results in 10 min with a detection range from 1×10−2-1×104 nM and a lower limit of detection (LOD) of 0.8 pM. The LOD of the study was at least one order of magnitude lower than that of the fluorescence detection method. Furthermore, the accuracy of the aptasensor was validated for spiked recovery experiments.

A novel electrochemiluminescence aptasensor for ultrasensitive lincomycin detection using Ti3C2–TiO2–Ru probe

The presence of lincomycin (LIN) residues in food poses significant health risks to humans, necessitating a highly sensitive and specific detection method for LIN. This study used a self-enhancing Ti3C2–TiO2–Ru probe to develop an electrochemiluminescence aptasensor to detect LIN. The Ti3C2–TiO2 was synthesized in situ by harnessing the unique reducibility of Ti3C2, with TiO2 serving as a co-reaction accelerator. Moreover, Ti3C2–TiO2 served as a carrier with an excellent negative charge, allowing for the immobilization of a substantial amount of Ru(bpy)32+ through electrostatic adsorption, thus forming a self-enhancing Ti3C2–TiO2–Ru probe. Furthermore, the specific affinity of LIN toward the aptamer and the chelating interaction between the Ti and phosphate groups ensured highly precise LIN detection. This sensor demonstrated excellent performance, with a detection limit of 0.025 ng mL−1 and a detection range of 1.0 × 10−1–1.0 × 104 ng mL−1. The LIN detection in milk showed commendable recovery rates, ranging from 94.4% to 106.0%.

Nanochannel-confined platinum nanostructure for enhancement of luminol-dissolved oxygen electrochemiluminescence coupled with gated aptasensor for sensitive detection of carcinoembryonic antigen

Rapid and precise detection of tumor biomarkers in serum is of great significance for early diagnosis, treatment assessment, and recurrence monitoring of cancers. The fabrication of user-friendly electrochemiluminescence (ECL) aptasensors with effective signal amplification is highly desirable. In this study, an ECL aptasensor was developed with luminol-based ternary ECL platform using dissolved oxygen as endogenous co-reactant and nanochannel-confined platinum nanoparticles (PtNPs) as co-reactant promoter, which can realize highly sensitive detection of the tumor biomarker, carcinoembryonic antigen (CEA). On the cost-effective indium tin oxide (ITO) electrode, amino-modified vertically-ordered mesoporous silica film (NH2-VMSF) was easily grown to form high-density nanochannel array with ultrasmall nanochannels. PtNPs were then in-situ synthesized within the nanochannels via electrodeposition. Ternary ECL system was successfully fabricated as confined PtNPs can catalyze the electroreduction of dissolved oxygen at negative potentials as well as electrochemical oxidation of luminol, enhancing the ECL signal of luminol. The recognitive aptamer (Apt) was covalently immobilized on the outer surface of NH2-VMSF, resulting in the fabrication of an aptasensor. In presence of CEA, a decreased ECL signal was obtained as the formed complex on the recognition interface hindered the diffusion of ECL emitter to the supporting electrode. Based on this signal turn-off mode, sensitive detection of CEA was achieved ranged from 10 fg mL−1 to 100 ng mL−1, with a low detection limit (DL, 0.4 fg mL−1). The aptasensor displayed high selectivity and good reproducibility. The nanochannel-based aptasensor and ternary ECL system demonstrates great potential in convenient and sensitive detection of cancer biomarker.

Design and application of an ultrasensitive and selective tobromycin electrochemiluminescence aptasensor using MXene /Ni/Sm-LDH-based nanocomposite.

Using a chemiluminescence reaction between luminol and H2O2 in basic solution, an ultrasensitive electrochemiluminescence (ECL) aptasensor was developed for the determination oftobramycin (TOB), as an aminoglycoside antibiotic. Ti3C2/Ni/Sm-LDH-based nanocomposite effectively catalyzes the oxidation of luminol and decomposition of H2O2, leading to the formation of different reactive oxygen species (ROSs), thus amplifying the ECL signal intensity of luminol, which can be used for the determination of TOB concentration. To evaluate the performance of the electrochemiluminescence aptasensor and synthesized nanocomposite, different methods such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses were performed. The considerable specific area, large number of active sites, and enhanced electron transfer reaction on this nanocomposite led to the development of an ECL aptasensor with high sensitivity and electrocatalytic activity. After optimizing the preparation method and analysis conditions, the aptasensor revealed a wide linear response ranging from 1.0 pM to 1.0 μM with a detection limit of 18 pM, displaying outstanding accuracy, specificity, and response stability. The developed ECL sensor was found to be applicable to the determination of TOB in human serum samples and is anticipated to possess excellent clinical potentials for detecting other antibiotics, as well.

Novel electrochemiluminescence sensing platform for ultrasensitive detection of malathion residue in tea based on SiO2NSs doped Luminol/AgNPs as a signal amplification strategy

To address the potential hazards of organophosphorus pesticides (OPs) residues in tea, an electrochemiluminescence (ECL) aptasensor based on functionalized nanomaterials was constructed in this work. Firstly, gold nanoparticles (AuNPs) were attached on the surface of multi-walled carbon nanotubes (MWCNTs) by the constant potential electrodeposition to form a compound, and it was utilized to provide excellent immobilization sites for complementary DNA (cDNA). Subsequently, composite nanomaterials were synthesized by a one-pot method with aminated Luminol/silver nanoparticles@silica nanospheres (NH2-Luminol/Ag@SiO2NSs). Finally, NH2-Luminol/Ag@SiO2NSs was combined with a malathion aptamer (Apt) to obtain signal probes (SPs) for the construction of an aptasensor. The aptasensor had a wide linear range (1×10−3-1×103 ng/mL) and a low limit of detection (LOD) (0.3×10−3 ng/mL). It had the virtues of high sensitivity, wonderful stability and excellent specificity, which could be used for the detection of malathion residue in tea. The work provides a proven way for the construction of a rapid and ultrasensitive aptasensor with low-cost.

Ultrasensitive Electrochemiluminescence Biosensing Platform Based on Polymer Dots with Aggregation-Induced Emission for Dual-Biotoxin Assay.

Multitarget assay has always been a hot topic in electrochemiluminescence (ECL) methods. Herein, a "on-off-on" ECL aptasensor was developed for the ultrasensitive and sequential detection of possible biological warfare agents, deoxynivalenol (DON) and abrin (ABR). As a luminophore, polymer dots (Pdots) with aggregation-induced emission exhibit high ECL efficiency in the aptasensor, i.e., the signal "on" state. The DON assays mainly depend on ECL quenching due to the efficient quenching effect between ferrocene-H2-ferrocene (Fc-H2-Fc) and Pdots, i.e., the signal "off" state. When the aptasensor is incubated with the oligonucleotide sequence S2 to replace Fc-H2-Fc, obvious ECL recovery occurs, i.e., the signal "on" state, which can be used to sequentially detect ABR. The limit of detection (LOD) for DON is 0.73 fg·mL-1 in the range of 5.0 to 50 ng·mL-1; and the LOD for ABR is ∼0.38 pg·mL-1 in the range of 1.25 pg·mL-1 to 1.25 μg·mL-1. The as-designed ECL aptasensor exhibits good stability and reproducibility, high specificity, and favorable practicality. Therefore, this work provides a new approach for assays of DON and ABR in food safety and can be used as a model to design an ultrasensitive ECL biosensor for multitarget detection.

A highly efficient homogeneous electrochemiluminescence aptasensor for amplified analysis of Ochratoxin A

Ochratoxin A (OTA) is a toxic thermostable subordinate metabolite produced by Aspergillus and Penicillium species. OTA contamination occurs in a wide range of foods and poses a threat to human health. Therefore, it is crucial to construct a sensitive and reliable method for analyzing OTA to ensure food safety. Herein, a simple yet sensitive ECL aptasensor has been constructed for OTA detection through the synergistic amplification between catalytic DNA assembly (CDA) and exonuclease III (Exo III)-initiated recycling reaction. The anti-OTA aptamer-encoded sensing unit specifically recognizes target OTA and leads to the release of the trigger sequence for stimulating the CDA circuit, yielding numerous dsDNA hybrids that carry the re-assembled S strand. Each of the as-assembled S sequence could hybridize with the Ru(bpy)32+-labeled substrate (S*-Ru) to produce a T-shape structure with a blunt 3′ terminus, which can be hydrolyzed and digested by Exo III, leading to the liberation of mononucleotide functionalized with Ru(bpy)32+ (Ru). Simultaneously, the S sequence was released and hybridized with another S*-Ru sequence for initiating the subsequent cycle of Exo III-stimulated digestion process until all the S*-Ru strands are digested, thus resulting in the generation of numerous Ru and remarkably amplified ECL signals for high-performance detection of OTA. With reliable analyte recognition and high signal gain, the ECL system enabled the high-performance and accurate determination of OTA in buffer, wheat, and wine samples, thus showing considerable potential applications for highly efficient determination of contaminants of low concentration in foodstuff.

Stable detection of diazinon residues in vegetables by an electrochemiluminescent aptasensor based on the in-situ production of H2O2 from dual-catalytic glucose

Stable detection of diazinon (DZN) residues in vegetables is important for food safety. In this work, an electrochemiluminescence (ECL) aptasensor with dual-catalytic glucose in-situ production of H2O2 was constructed for the stable detection of DZN in vegetables. Firstly, MWCNTs@MB was prepared using π-π stacking interactions between methylene blue (MB) and multi-walled carbon nanotubes (MWCNTs) to enhance the loading of MB on an electrode and thus catalyze the generation of H2O2 from glucose. Secondly, Cu2O@AuNPs was formed by loading AuNPs on the surface of Cu2O through spontaneous reduction reaction, which improved the interfacial charge transfer, Cu2O nano-enzyme had glucose oxidase mimicking activity and could further catalyze the production of more H2O2 from glucose. MWCNTs@MB and Cu2O@AuNPs played a key role in the in-situ generation of co-reacting reagent H2O2, which solved the problem of unstable detection caused by the easy decomposition of the H2O2 solution added to the luminescence system. In addition, the aptamer was immobilized on the electrode surface by forming Au–S bonds with Cu2O@AuNPs. As a result, the ECL aptasensor performed good linearity in 1.00 pg mL−1-1.00 μg mL−1 and a low limit of detection (LOD) to 0.39 pg mL−1 (S/N = 3). This work provided an effective method for the accurate and stable detection of DZN residues in vegetables, which was of great significance in ensuring food safety and assessing the environmental risk of DZN.

Detection of urokinase based on ECL resonance energy transfer between block copolymers encapsulated iridium complex and ReS2 nanosheets

The encapsulation of water insoluble iridium complex in SiO2 nanoparticles can be used to fabricate aqueous electrochemiluminescence (ECL) sensor, however, the ECL signal is greatly reduced. It is urgent to explore more suitable method to encapsulate iridium complex and improve its ECL efficiency. Pluronic block copolymers has good biocompatibility and high load capacity, which might be used to encapsulate iridium complex. In the present work, one kind of concentric nanospheres were assembled by encapsulating iridium complexes into block copolymers using poly (styrene-co-maleicanhydride) (PSMA@Ir). Strong anodic ECL signal was obtained at PSMA@Ir nanospheres modified electrode without additional coreactant. The light absorption character of ReS2 nanosheets (ReS2NS) endowed it the ability to accept energy from PSMA@Ir ECL. As a result, a novel ECL resonance energy transfer (ECL-RET) system was constructed with PSMA@Ir as energy donor while ReS2NS as energy acceptor. Based on the above results, an ECL aptasensor was designed to detect urokinase (UPA). The ECL intensity changed linearly with the logarithm of UPA concentration in the range of 1.0 × 10−16–1.0 × 10−12 mol/L with a detection limit of 2.95 × 10−17 mol/L. The prepared sensor owned high sensitivity and selectivity, and provided new avenue for the application of water insoluble iridium complex in ECL sensing.

A novel “on-off-on” electrochemiluminescence aptasensor based on resonance energy transfer as signal amplification strategy for ultrasensitive detection of sulfadiazine in different samples

The misuse of antibiotics may contaminate the environment and cause harm to human health. Therefore, rapid and accurate detection of antibiotics is essential. In this study, a novel electrochemiluminescence resonance energy transfer (ECL-RET) pair was designed using a new ECL emitter (CPM, Ce-TBAPy) as the donor and Co-MOF@AuPt as the acceptor. Moreover, a highly sensitive and specific “on-off-on” ECL aptasensor was constructed for detecting sulfadiazine (SDZ). The aptasensor exhibited a broad linear range (from 10.0 fg mL−1 to 100 ng mL−1) for the SDZ concentration, with limit of detection and limit of quantification values of 1.14 fg mL−1and 3.75 fg mL−1, respectively. The aptasensor achieved good results in spiking experiments with milk and egg samples, and successfully quantified SDZ in fish meal quality control sample. The prepared aptasensor presents great potential for food and environmental safety by detecting antibiotics.

Electrochemiluminescence aptasensor toward femtomolar detection of alpha synuclein oligomer as parkinson's disease marker using CdTe@ZnS quantum dots as luminescent label and graphdiyne@polyaniline as novel co‐reactant

AbstractParkinson's disease (PD) as a progressive health issue effects on the central nervous system. It is well established that soluble ‐synuclein (−syn) oligomers cause neuronal death in the earliest stages of PD. So, development of sensitive and selective method for a‐syn analysis is a challenge. Here an electrochemiluminescence (ECL) aptasensor designed for selective and ultrasensitive detection of α‐syn oligomer using graphdiyne@polyaniline with N‐doped active sites (GDY@PANI) as novel coreactant agent combined with CdTe@ZnS QD as luminescent lable for amplified self‐enhanced electrochemiluminescence (ECL) response. For the first time a novel ECL sensing platform based on GDY@PANI/CdTe@ZnS QD composite was designed using new co‐reactant based on GDY. Compared to CdTe@ZnS QD, GDY/CdTe@ZnS QD, CdTe@ZnS QD/tri‐propylamine and PANI/CdTe@ZnS QD, the GDY@PANI/CdTe@ZnS QD composite exhibited amplified ECL emissions and ECL efficiency of the proposed system also increased compared to more QDs based ECL systems. Under the optimal conditions, the proposed ECL aptasensor exhibited a wide linear range of 0.2 fM to 8 nM for α‐syn oligomer determination with a low detection limit of 0.02 fM (S/N=3). The fabricated sensor has advantages of good reproducibility, high sensitivity and stability and being capable of detecting α‐syn oligomer in human blood serum and also lysate of dopaminergic nerve cells. The obtained results confirmed that the GDY@PANI can be used as a novel co‐reactant in development of the ECL based bio devices with great potential applicability for biomarkers analysis, diagnosis and management of Parkinson or other diseases.

Electrochemiluminescent (ECL) Aptasensor for Lysozyme Using a Graphene Quantum Dot (GQD)-Ruthenium Bipyridine-Silica Nanocomposite

An electrochemiluminescent (ECL) aptasensor for lysozyme (Lyz) based on a graphene quantum dot (GQD)-ruthenium bipyridine (Ru(bpy)3 2+)-silica (GQDs-Ru(bpy)3 2+@SiO2) nanocomposite were prepared by encapsulating GQDs and the luminophore Ru(bpy)3 2+ in silica nanospheres (SiO2). The nanocomposite GQDs-Ru(bpy)3 2+@SiO2 with uniform size exhibited a strong and reproducible ECL response. The nanoprobe (DNA-GQDs-Ru(bpy)3 2+@SiO2) was obtained via amidation between GQDs-Ru(bpy)3 2+@SiO2 and the complementary DNA sequence. The ECL platform was constructed by hybridization between the aptamer and the complementary strand DNA. The specific recognition between aptamer and the target lysozyme maintained the nanoprobe DNA-GQDs-Ru(bpy)3 2+@SiO2 away from the electrode, which led to the decreasing ECL response. The aptasensor exhibited a linear relationship from 0.1 to 100 pg/mL with a detection limit of 1.7 × 10−11 mg/mL. This study provided a simple and sensitive analytical approach for lysozyme.

Solvent Regulation Induced Cathode Aggregation-Induced Electrochemiluminescence of Tetraphenylethylene Nanoaggregates for Ultrasensitive Zearalenone Analysis.

Zearalenone (ZEN) is an extremely hazardous chemical widely existing in cereals, and its high-sensitivity detection possesses significant significance to human health. Here, the cathodic aggregation-induced electrochemiluminescence (AIECL) performance of tetraphenylethylene nanoaggregates (TPE NAs) was modulated by solvent regulation, based on which an electrochemiluminescence (ECL) aptasensor was constructed for sensitive detection of ZEN. The aggregation state and AIECL of TPE NAs were directly and simply controlled by adjusting the type of organic solvent and the fraction of water, which solved the current shortcomings of low strength and weak stability of the cathode ECL signal for TPE. Impressively, in a tetrahydrofuran-water mixed solution (volume ratio, 6:4), the relative ECL efficiency of TPE NAs reached 16.03%, which was 9.2 times that in pure water conditions, and the maximum ECL spectral wavelength was obviously red-shifted to 617 nm. In addition, "H"-shape DNA structure-mediated dual-catalyzed hairpin self-assembly (H-D-CHA) with higher efficiency by the synergistic effect between the two CHA reactions was utilized to construct a sensitive ECL aptasensor for ZEN analysis with a low detection limit of 0.362 fg/mL. In conclusion, solvent regulation was a simple and efficient method for improving the performance of AIECL materials, and the proposed ECL aptasensor had great potential for ZEN monitoring in food safety.

Rapid and simple viral protein detection by functionalized 2D MoS2/graphene electrochemiluminescence aptasensor

In this work we present the development of an electrochemiluminescence aptasensor based on electrografting molybdenum disulphide nanosheets functionalized with diazonium salt (MoS2–N2+) upon screen-printed electrodes of graphene (SPEs GPH) for viral proteins detection. In brief, this aptasensor consists of SPEs GPH electrografted with MoS2–N2+ and modified with a thiolated aptamer, which can specifically recognize the target protein analyte. In this case, we have used SARS-CoV-2 spike protein as model protein. Electrochemiluminescence detection was performed by using the [Ru(bpy)3]2+/TPRA (tripropylamine) system, which allows the specific detection of the SARS-CoV-2 spike protein easily and rapidly with a detection limit of 9.74 fg/mL and a linear range from 32.5 fg/mL to 50.0 pg/mL. Moreover, the applicability of the aptasensor has been confirmed by the detection of the protein directly in human saliva samples. Comparing our device with a traditional saliva antigen test, our aptasensor can detect the spike protein even when the saliva antigen test gives a negative result.