A novel electrochemiluminescence aptasensor for protein based on a sensitive N-(aminobutyl)-N-ethylisoluminol-functionalized gold nanoprobe

A novel electrochemiluminescence (ECL) aptasensor for platelet-derived growth factor B chain (PDGF-BB) assay was developed by assembling N-(aminobutyl)-N-ethylisoluminol functionalized gold nanoparticles (ABEI-AuNPs) with aptamers as nanoprobes. In the protocol, the biotinylated aptamer capture probes were first immobilized on a streptavidin coated gold nanoparticle (AuNPs) modified electrode, afterwards, the target PDGF-BB and the ABEI-AuNPs tagged aptamer signal probe were successively attached to the modified electrode by virtue of the dimer structure of PDGF-BB to fabricate a "sandwich" conjugate modified electrode, i.e. an aptasensor. ECL measurement was carried out with a double-step potential in carbonate buffer solution containing H(2)O(2). The aptasensor showed high sensitivity and selectivity toward PDGF-BB and specificity toward PDGF-BB aptamer. The detection limit was as low as 2.7 × 10(-14) M. In this work, the ABEI-AuNPs synthesized by a simple seed growth method have been successfully used as aptamer labels, which greatly amplified the ECL signal by binding numbers of ABEI molecules on the surface of AuNPs. The ABEI-AuNPs signal amplification is superior to other reported signal amplification strategies based on aptamer-related polymerase chain reaction or functionalized nanoparticles in simplicity, stability, labeling property and practical applicability. And the ABEI-AuNPs based nanoprobe is more sensitive than the luminol functionalized AuNPs based nanoprobe. Moreover, such an ultra-sensitive and low-cost assay can be accomplished with a simple and fast procedure by using a simple ECL instrumentation. The aptasensor was also applied for the detection of PDGF-BB in human serum samples, showing great application potential. Given these advantages, the ECL aptasensor is well suited for the direct, sensitive and rapid detection of protein in complex clinical samples.     

基于DNA电化学发光传感器研究金纳米颗粒对量子点的电化学发光影响

纳米金颗粒具有高的消光系数和良好的表面等离子体共振特性, 其等离子体共振特性受纳米金颗粒的尺寸和周围环境等因素的影响. 本文基于半导体纳米晶电化学发光信号对金纳米颗粒的距离依赖性制备了DNA电化学发光传感器. 首先利用循环伏安法(CV)在玻碳电极(GCE)表面原位沉积金纳米颗粒(AuNPs), 巯基丙酸包裹的CdS量子点(QDs)与氨基修饰的双链DNA (dsDNA)通过酰胺键缩合, 形成量子点修饰的双链DNA(QDs-dsDNA). 最后将QDs-dsDNA 通过dsDNA 另一端的巯基组装到纳米金表面, 得到CdS QDs-DNA/AuNPs/GCE电化学发光传感器. 在优化电极表面QDs-dsDNA密度、金纳米颗粒沉积方法等实验条件的基础上, 对不同传感器的表面性质进行了表征, 如形貌和电化学阻抗等. 进一步通过控制纳米金和CdS QDs之间的DNA研究了纳米金对CdS QDs发光信号的影响作用. 结果显示DNA链的长度和类型对发光信号有着重要的影响. 最后将此传感器用于环境污染物的DNA损伤检测, 显示出很好的灵敏响应.     

A electrochemiluminescence aptasensor for detection of thrombin incorporating the capture aptamer labeled with gold nanoparticles immobilized onto the thio-silanized ITO electrode

A novel electrochemiluminescence (ECL) aptasensor was proposed for sensitive and cost-effective detection of the target thrombin adopted an aptamer-based sandwich format. To detect thrombin, capture aptamers labeled with gold nanoparticles (AuNPs) were first immobilized onto the thio-silanized ITO electrode surface through strong Au-S bonds. After catching the target thrombin, signal aptamers tagged with ECL labels were attached to the assembled electrode surface. As a result, an AuNPs-capture-aptamer/thrombin/ECL-tagged-signal-aptamer sandwich type was formed. Treating the resulting electrode surface with tri-n-propylamine (TPA) and applying a swept potential to the electrode, ECL response was generated which realized the detection of target protein. Spectroscopy and electrochemical impedance techniques were used to characterize and confirm the fabrication of the ECL aptasensor. AuNPs amplification and smart sensor fabrication art were implemented for the sensitive and cost-effective detection purpose. Signal-to-dose curve excellently followed a sandwich format equation and could be used to quantify the protein, and the detection limit was estimated to be 10 nM. Other forms of thrombin such as β- and γ-thrombins had negligible response, which indicated a high specificity of α-thrombin detection. The aptasensor opened up new fields of aptamer applications in ECL domain, a highly sensitive technique, and had a promising perspective to be applied in microarray analysis.     

基于Ru(bpy)32+/AuNPs/Nafion电化学发光传感器检测已烯雌酚

利用柠檬酸钠还原氯金酸制得金纳米粒子(AuNPs),基于AuNPs/Nafion与Ru(bpy)32+之间的静电引力,制备了Ru (bpy) 32+/AuNPs/Nafion电化学发光传感器.采用循环伏安法和电化学发光法对该传感器进行了表征,结果表明该传感器具有良好的稳定性和重现性,可实现对已烯雌酚的检测.在pH=7.0的0.1 mol/L磷酸盐缓冲溶液(PBS,含0.05 mol/L三正丙胺)中,当已烯雌酚与修饰电极作用15 min时,电化学发光强度减少值与已烯雌酚浓度的负对数在1.0×10-10～5.0×10-7 mol/L范围内呈良好的线性关系,检出限为6.0 X 10-11 mol/L.对1.0×10-8 mol/L已烯雌酚平行测定11次,相对标准偏差为2.7％.测定已烯雌酚实际样品的加标回收率在98.0％～104.5％之间.     

In situ synthesis of gold nanoparticles on porous polyacrylonitrile nanofibers for sensing applications

A simple and cost-effective method was reported to synthesize small size (6 nm) gold nanoparticles (AuNPs) on polyacrylonitrile (PAN) electrospun nanofibers (AuNPs/PAN). The formation of AuNPs is attributed to the in situ reduction of Au(III) to Au(0) by 4-(dimethylamino)benzaldehyde doped in the PAN nanofibers. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) confirmed that the AuNPs/PAN nanofibers showed good conductivity. The AuNPs/PAN nanofibers were used to immobilize tris(2,2'-bipyridyl)ruthenium(II) ions (Ru(bpy)(3)(2+)) to form an electrochemiluminescence (ECL) sensor. The AuNPs on the PAN nanofibers exhibited an excellent catalytic effect on the ECL of Ru(bpy)(3)(2+) which could be employed to detect low concentrations of phenolic compounds. The linear response range of the ECL sensor to hydroquinone is 0.55-37 μM with limit of detection of 80 nM (S/N = 3). This sensor has been successfully applied to determine the hydroquinone content in photographic developer samples. Our work provides a very simple and cost-effective method to synthesize AuNPs on polymer nanofibers which shows great potential in the field of electrocatalysis and chemo/biosensors.     

Ultrasensitive electrochemiluminescence immunosensor using PtAg@carbon nanocrystals composites as labels and carbon nanotubes-chitosan/gold nanoparticles as enhancer

An ultrasensitive electrochemiluminescence (ECL) immunosensor was developed using PtAg@carbon nanocrystals (CNCs) as excellent labels based on carbon nanotubes-chitosan/AuNPs (CNT-CHIT/AuNPs) composite modified screen-printed carbon electrodes (SPCEs) for prostate protein antigen (PSA) detection. The CNCs were obtained simply by electro-oxidation of graphite with abundant carboxyl groups at their surfaces. The PtAg bimetallic nanocomposites with hierarchically hollow structures were fabricated through simple replacement reaction using dealloyed nanoporous silver (NPS) as both a template and reducing agent. Structure characterization was obtained by means of transmission electron microscope (TEM) and scanning electron microscope (SEM) images. The PtAg@CNCs composites exhibit a 6 times higher ECL intensity than the pure CNCs labeled anti-PSA. The as-prepared CNT-CHIT/AuNPs composite can attach more antibody than pure CNTs. Due to the dual-amplification techniques, the concentrations of PSA were obtained in the range from 1 pg mL(-1) to 50 ng mL(-1) with a detection limit of 0.6 pg mL(-1). Finally, the as-proposed ECL immunosensor has the advantages of high sensitivity, specificity and stability and could become a promising technique for tumor marker detection.     

Small Size Effect and Concentration Response of Gold Nanoparticles in Electrochemiluminescence Reaction

Recent reports have used gold nanoparticles (AuNPs) as a co‐reactant for the electrochemiluminescence (ECL) reaction of ruthenium complex. However, understanding the size effect of AuNPs on ECL reaction is very meaningful to explore its unknowns and develop its applications at the molecular level. In this paper, we examined the behavior of various small‐size AuNPs in ECL reaction, focusing on changes in ECL caused by AuNPs size and reasons for this change. Although the luminescence spectra and excitation potential have hardly changed in ECL reaction, the difference of ECL intensities induced by different sizes AuNPs is very obviously. Our experimental results revealed disparate behaviors depending on AuNPs size: the small‐sized AuNPs can lead to stronger ECL, and ECL intensities increase as the addition of AuNPs concentration in the wider range. This small size effect is related to an intermediate process of charge‐discharge in electric double layer formed by adsorbing ruthenium complex with AuNPs, and the surface and quantum size effect of AuNPs may affect this intermediate process. More importantly, AuNPs can act as a marker, has the same small size effect and concentration response, and bring about a promising platform for biochemical analysis.     

Electrochemiluminescence Immunosensor Based on Functionalized Graphene/Fe3O4‐Au Magnetic Capture Probes for Ultrasensitive Detection of Tetrodotoxin

An ultrasensitive electrochemiluminescence (ECL) immunosensor for the detection of tetrodotoxin (TTX) is proposed, which are composed of the branched poly‐(ethylenimine) (BPEI) functionalized graphene (BGNs)/Fe₃O₄‐Au magnetic capture probes and luminol‐capped gold nanocomposites (luminol‐AuNPs) as the signal tag. Herein, a typical sandwich immunecomplex was constructed on the glassy carbon electrode. The BGNs/Fe₃O₄‐Au hybrids could efficiently conjugate primary antibody via the Au−S chemical bonds or Au−N chemical bonds and rapidly separate under external magnetic field. The introduction of BPEI to GO could enhance the luminol‐ECL intensity. Meanwhile, the multifunctional nanocomposites have been proved with good water‐solubility, excellent electron transfer, outstanding stability, etc. The luminescent luminol‐AuNPs, a high efficient electrochemiluminescence marker, can be assembled on the second antibody, which can produce the ECL signal to achieve the determination of TTX. This proposed ECL immunosensor with a linear range from 0.01–100 ng/mL can be applied in the detection of TTX in real samples with satisfactory results.     

“Signal-on” Electrogenerated Chemiluminescence Biosensing Method for the Determination of Matrix Metalloproteinase 2

A simple, selective and sensitive “signal-on” electrogenerated chemiluminescence (ECL) biosensing method was developed for matrix metalloproteinase 2 (MMP-2). Ru(bpy)₃²⁺, gold nanoparticles (AuNPs) and Nafion were modified onto glassy carbon electrode (GCE) to form Ru(bpy)₃²⁺/AuNPs/Nafion/GCE as sensitive ECL platform and then ferrocene (Fc) labeled peptide was assembled onto the modified electrode to form ECL biosensing platform. The ECL intensity increased when the ECL biosensing electrode reacted with MMP-2 because of MMP-2-induced cleavage of Fc labeled peptide. The ECL method was applied to determine MMP-2 with detection limit of 0.3 ng/mL and one-step recognition, which is promising for point-of-care test of protease.     

Fluorescence and electrochemiluminescence of luminol-reduced gold nanoparticles: photostability and platform effect

Water-soluble gold nanoparticles (AuNPs) capped with both fluorescent (FL) 3-aminophthalate (APA) and electrochemiluminescent (ECL) luminol molecules were described in our previous work. The synthetic and characteristic efforts of these functionalized AuNPs (lumAuNPs) were subsequently followed by investigations of their FL and ECL properties, as reported in the present work. It was observed that the FL intensity of a single gold nanoparticle was 70 times brighter than that of one free APA molecule, even though 91% of the FL emission of APA molecules on the surfaces of AuNPs was inhibited by gold cores through both intra- and interparticle quenching effects. Moreover, the photobleaching of surface-bound APA molecules was found to be dramatically inhibited compared with that of free ones in carbonate buffer. The improvement of photostability was attributed to the reactive AuNPs which acted as radical scavengers to protect the surface-bound APA molecules from oxidation by carbonate radicals. Furthermore, as-prepared lumAuNPs could react with cysteine to produce strong electrochemiluminescence, which was enhanced by 20-fold compared with that in the absence of cysteine. The experimental results suggested that luminol and cysteine were coadsorbed on the gold nanoparticle platform via Au-N and Au-S interactions, respectively. The shorter distance between reactant molecules by overcoming the electrostatic repulsion, that is, platform effect, was proposed to be responsible for the ECL enhancement. Combined with the biocompatibility of gold cores, the brighter FL emission, enhanced photostability, and stronger ECL intensity may make as-prepared lumAuNPs promising FL and ECL biomarkers for their applications in biosensors and bioimaging.     

Electrochemiluminescent determination of cancer cells based on aptamers, nanoparticles, and magnetic beads

Herein we report a polymerase chain reaction (PCR)-free electrochemiluminescence (ECL) approach that uses ECL nanoprobes for the determination of cancer cells with high sensitivity. The ECL nanoprobe consists of gold nanoparticles (AuNPs), linker DNA, and tris(2,2'-bipyridyl)ruthenium (TBR)-labeled signal DNA. The linker DNA and signal DNA were modified on the surface of the AuNPs through Au-S bonds. The linker DNA can partly hybridize with the aptamers of cancer cells loaded onto the magnetic beads (MB1) to construct the magnetic biocomplexes. In the presence of the cancer cells, the aptamers conjugated with the cancer cells with higher affinity. The ECL nanoprobe was released from the biocomplexes and subsequently hybridized with the capture DNA loaded onto another magnetic bead (MB2) to form the magnetic nanocomposite. The nanocomposites can be easily separated and firmly attached to an electrode on account of their excellent magnetic properties. The ECL intensity of the TBR loaded onto the nanocomposites directly reflected the amount of cancer cells. By using cell lines of Burkitt's lymphoma (Ramos cells) as a model, the ECL response was proportional to the cell concentration in the range from 5 to 100 cells ml(-1); a limit of detection as low as 5 cells ml(-1) of Ramos cells could be achieved. The proposed method described here is ideal for the diagnosis of cancers due to its high sensitivity, simplicity, and low cost.     

金纳米球/氮掺杂石墨烯量子点固载Ru(bpy)3^2+电致化学发光法检测邻苯二酚

利用还原法制得金纳米球(Au NPs),与氮掺杂石墨烯量子点(NG QDs)杂化后,再以壳聚糖胶黏剂并通过静电作用使Ru(bpy)3^2+负载于其表面形成复合膜,制备了一种新型的固相电致化学发光(ECL)传感器。研究发现,与单一材料相比,Au NPs和NG QDs杂化复合材料作为载体显著提高了发光试剂Ru(bpy)3^2+的ECL信号。根据环境污染物邻苯二酚对该修饰电极ECL信号较强的阻抑作用,建立了测定领苯二酚的新体系。结果表明,Au NPs/NG QDs/Ru(bpy)3^2+修饰电极的ECL信号变化值与邻苯二酚的浓度负对数在5.0 nmol/L^10μmol/L之间呈良好的线性关系,检出限为3.0 nmol/L(r=0.9992)。对5.0μmol/L的邻苯二酚进行10次重复测定,相对标准偏差为4.6%,常见的共存物质不干扰测定,表明该方法的选择性较好。采用该修饰电极成功测定了河水中的邻苯二酚含量。     

Highly enhanced electrochemiluminescent strategy for tumor biomarkers detection with in situ generation of l-homocysteine for signal amplification

In this work, an ultrasensitive peroxydisulfate electrochemiluminescence (ECL) immunosensor using in situ generation of l-homocysteine (l-Hcys) for signal amplification was successfully constructed for detection of carcinoembryonic antigen (CEA). In the reaction of biological methylation, S-adenosyl-l-homocysteine hydrolase (SAHH) catalyzed the reversible hydrolysis of S-adenosyl-l-homocysteine (SAH) to produce l-Hcys, which was inducted into ECL system to construct the immunosensor for signal amplification in this work. Simultaneously, Gold and palladium nanoparticles functionalized multi-walled carbon nanotubes (Au-PdNPs@MWCNTs) were prepared, which were introduced to immobilize the secondary antibody (Ab₂) and SAHH with high loading amount and good biological activity due to their improved surface area and excellent biocompatibility. Then the proposed ECL immunosensor was developed by a sandwich-type format using Au-PdNPs@MWCNTs-SAHH-Ab₂ as tracer and graphene together with AuNPs as substrate. Besides the enhancement of Au-PdNPs, the enzymatic catalysis reaction also amplified the ECL signal dramatically, which was achieved by efficient catalysis of the SAHH towards the hydrolysis of SAH to generate improved amount of l-Hcys in situ. Furthermore, due to the special interaction between Au-PdNPs and -SH or -NH₂ in l-Hcys, l-Hcys would gradually accumulate on the surface of the immunosensor, which greatly enhanced the concentration of l-Hcys on the immunosensor surface and further improved the ECL intensity. With the amplification factors above, a wide linear ranged from 0.1 pg mL⁻¹ to 80 ng mL⁻¹ was acquired with a relatively low detection limit of 33 fg mL⁻¹ for CEA.     

Synthesis, characterization, and electrochemiluminescence of luminol-reduced gold nanoparticles and their application in a hydrogen peroxide sensor

It was found that chloroauric acid (HAuCl(4)) could be directly reduced by the luminescent reagent luminol in aqueous solution to form gold nanoparticles (AuNPs), the size of which depended on the amount of luminol. The morphology and surface state of as-prepared AuNPs were characterized by transmission electron microscopy, UV/visible spectroscopy, X-ray photoelectron spectroscopy, FTIR spectroscopy, and thermogravimetric analysis. All results indicated that residual luminol and its oxidation product 3-aminophthalate coexisted on the surface of AuNPs through the weak covalent interaction between gold and nitrogen atoms in their amino groups. Subsequently, a luminol-capped AuNP-modified electrode was fabricated by the immobilization of AuNPs on a gold electrode by virtue of cysteine molecules and then immersion in a luminol solution. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The as-prepared modified electrode exhibited an electrochemiluminescence (ECL) response in alkaline aqueous solution under a double-step potential. H2O2 was found to enhance the ECL. On this basis, an ECL sensor for the detection of H2O2 was developed. The method is simple, fast, and reagent free. It is applicable to the determination of H2O2 in the range of 3x10(-7)-1x10(-3) mol L(-1) with a detection limit of 1x10(-7) mol L(-1) (S/N=3).     

Electrochemiluminescence based determination of micro-RNA using target-guided assembly of gold nanoparticles on an electrode modified with Nafion,carbon nanotubes and polyvinylpyrrolidone

Microchimica Acta - The authors describe a sensing interface that is capable of selectively adsorbing gold nanopartices (AuNPs). It was applied to electrochemiluminescent (ECL) detection of...     

Multiple signal amplified electrochemiluminescent immunoassay for brombuterol detection using gold nanoparticles and polyamidoamine dendrimers-silver nanoribbon

Electrochemiluminescent (ECL) immunosensor with multiple signal amplification was designed based on gold nanoparticles (AuNPs), polyamidoamine dendrimers (PAMAM) and silver-cysteine hybrid nanoribbon (SNR). Low toxic l-cysteine capped CdSe QDs was chosen as the ECL signal probe. To verify the proposed ultrasensitive ECL immunosensor for β-adrenergic agonists (β-AA), we detected Brombuterol (Brom) as a proof-of-principle analyte. Therein, AuNPs as the substrate can simplify the experiment process, accelerate the electron transfer rate, and carry more coating antigen (Ag-OVA) to enlarge ECL signal. On one hand, SNR on the surface of electrode can avoid the aggregation of AuNPs, and SNR-PAMAM-AuNPs also can be acted as a good accelerator for electron transfer. On the other hand, PAMAM (16 -NH₂) functionalized SNR (SNR-PAMAM) with numerous amino groups could be employed to bond abundant actived QDs to further amplify ECL signal. The new immunosensor can offer a simple, reliable, rapid, and selective detection for Brom, which have a dynamic range of 0.005–700 ng mL⁻¹ with a low detection limit at 1.5 pg mL⁻¹. The proposed biosensor will extend the application of nanomaterials in ECL immunoassays and open a new road for the detection of Brom and other β-AA in the future.     

An Electrochemiluminescence Biosensor for the Detection of Alzheimer’s Tau Protein Based on Gold Nanostar Decorated Carbon Nitride Nanosheets

Human Tau protein is the most reliable biomarker for the prediction of Alzheimer’s disease (AD). However, the assay to detect low concentrations of tau protein in serum is a great challenge for the early diagnosis of AD. This paper reports an electrochemiluminescence (ECL) immunosensor for Tau protein in serum samples. Gold nanostars (AuNSs) decorated on carbon nitride nanosheets (AuNS@g-CN nanostructure) show highly strong and stable ECL activity compared to pristine CN nanosheets due to the electrocatalytic and surface plasmon effects of AuNSs. As a result of the strong electromagnetic field at branches, AuNSs showed a better ECL enhancement effect than their spherical counterpart. For the fabrication of a specific immunosensor, immobilized AuNSs were functionalized with a monoclonal antibody specific for Tau protein. In the presence of Tau protein, the ECL intensity of the immunosensor decreased considerably. Under the optimal conditions, this ECL based immunosensor exhibits a dynamic linear range from 0.1 to 100 ng mL⁻¹ with a low limit of detection of 0.034 ng mL⁻¹. The LOD is less than the Tau level in human serum; thus, this study provides a useful method for the determination of Tau. The fabricated ECL immunosensor was successfully applied to the detection of Tau, the biomarker in serum samples. Therefore, the present approach is very promising for application in diagnosing AD within the early stages of the disease.     

Sensitive and versatile electrogenerated chemiluminescence biosensing platform for protein kinase based on Ru(bpy)3 functionalized gold nanoparticles mediated signal transduction

A novel, sensitive and versatile electrogenerated chemiluminescence biosensing platform is developed for monitoring activity and inhibition of protein kinase based on Ru(bpy)₃²⁺ functionalized gold nanoparticles (Ru(bpy)₃²⁺-AuNPs) mediated signal transduction. Ru(bpy)₃²⁺-AuNPs were formed by functionalizing AuNPs with Ru(bpy)₃²⁺ through electrostatic interactions and were used as thiol-versatile signal probe. Casein kinase II (CK2) and cAMP-dependent protein kinase (PKA), two classical protein kinase implicated in disease, were chosen as model protein kinases while a CK2-specific peptide (CRRRADDSDDDDD) and a PKA-specific peptide (CLRRASLG) were employed as molecular substrate for CK2 and PKA, respectively. The specific peptide was self-assembled onto the gold electrode via Au–S bond to form ECL biosensor. Upon thiophosphorylation of the peptide on the electrode in the presence of protein kinase and co-substrate adenosine-5’-(γ-thio)-triphosphate, Ru(bpy)₃²⁺-AuNPs was assembled onto the thiophosphorylated peptides via Au–S bond. The Ru(bpy)₃²⁺-AuNPs attached on electrode surface produce detectable ECL signal in the presence of coreactant tripropylamine. This strategy is promising for multiple protein kinase assay and kinase inhibitor profiling with high sensitivity, good selectivity and versatility. The ECL intensity is proportional to the activity of CK2 in the range of 0.01–0.5 unit/mL with a low detection limit of 0.008 unit/mL and to the activity of PKA in the range of 0.01–0.4 unit/mL with a detection limit of 0.005 unit/mL. Additionally, this assay was applied to the detection of CK2 in serum samples and the inhibition of CK2 and PKA. This work demonstrates that the developed ECL method can provide a sensitive and versatile platform for the detection of kinase activity and drug-screening.     

A Sandwich‐type Electrochemiluminescence Aptasensor for Thrombin Based on Functional Co‐polymer Electrode Using Ru(bpy)32+ Doped Nanocomposites as Signal‐amplifying Tags

Herein, a signal‐on sandwich‐type electrochemiluminescence (ECL) aptasensor for the detection of thrombin (TB) was proposed. The graphene (GR) doped thionine (TH) was electropolymerized synchronously on the bare glassy carbon electrode (GCE) to form co‐polymer (PTG) electrode. The gold nanoparticles (AuNPs) were decorated on the surface of the PTG by in‐situ electrodeposition, and the functional co‐polymer (PTG‐AuNPs) electrode was utilized as sensing interface. Then, TB binding aptamer I (TBA I) as capture probes were modified on the PTG‐AuNPs electrode to capture TB, and Ru(bpy)₃²⁺/silver nanoparticles doped silica core‐shell nanocomposites‐labeled TB binding aptamer II (RuAg/SiO₂NPs@TBA II) were used as signal probes to further bind TB, resulting in a sandwich structure. With the assistant of silica shell and AgNPs, the enrichment and luminous efficiency of Ru(bpy)₃²⁺ were significantly improved. Under the synergy of PTG‐AuNPs and RuAg/SiO₂NPs, the ECL signal was dramatically increased. The proposed ECL aptasensor displayed a wide linear range from 2 fM to 2 pM with the detection limit of 1 fM, which is comparable or better than that in reported ECL aptasensors for TB using Ru(bpy)₃²⁺ and its derivatives as the luminescent substance. The excellent sensitivity makes the proposed aptasensor a promising potential in pharmaceutical and clinical analysis.