Sensitive Detection Of Adenosine Triphosphate Research Articles

A novel dual-function fluorescence sensor Eu/CDs@MOF-808 for the sensitive detection of adenosine triphosphate and uric acid

Designing and developing a reliable method for the detection of potential biomarker molecules are crucial for the early prevention and diagnosis of diseases. In this study, we present a novel functionalized metal–organic framework material (MOF-808) that is developed to construct ratiometric fluorescence sensing platforms (Eu/CDs@MOF-808) for the detection of adenosine triphosphate (ATP) and uric acid (UA). The fluorescent probe Eu/CDs@MOF-808 prepared through the in-situ encapsulation of fluorescent carbon dots (CDs) within the structure of MOF-808 exhibits excellent optical properties. Additionally, rare earth ions (Eu3+) are incorporated into the CDs@MOF-808 using a post-synthetic modification strategy. The presence of ATP significantly enhances the characteristic peak of carbon dots (CDs) at 440 nm, while the peak of Eu3+ at 614 nm remains relatively unchanged. Furthermore, the concentration of ATP exhibits a strong linear relationship with the ratiometric fluorescence intensity (F440/F614) in the concentration range of 0.5–450 μM, with a detection limit of 0.22 μM. Notably, the addition of uric acid (UA) to this fluorescence sensing platform leads to a marked reduction in the characteristic peak intensity of Eu3+, which results in a satisfactory linear relationship between the ratiometric fluorescence intensity and UA concentration in the concentration ranges of 0.04–300 μM and 300–650 μM, with a detection limit of 0.04 μM. Additionally, the fluorescent sensor has been successfully applied for the detection of ATP and UA in real serum and urine samples.

Self-Matching Assembly of Chiral Gold Nanoparticles Leads to High Optical Asymmetry and Sensitive Detection of Adenosine Triphosphate.

To achieve chiral amplification, life uses small chiral molecules as building blocks to construct hierarchical chiral architectures that can realize advanced physiological functions. Inspired by the chiral amplification strategy of nature, we herein demonstrate that the chiral assembly of chiral gold nanorods (GNRs) leads to enhanced optical asymmetry factors (g-factors), up to 0.24. The assembly of chiral GNRs, dictated by structural self-matching, leads to g-factors with over 100-fold higher values than those of individual chiral GNRs, as confirmed by numerical simulations. Moreover, the efficient optical asymmetry of chiral GNR assemblies enables their application as highly sensitive sensors of adenosine triphosphate (ATP detection limit of 1.0 μM), with selectivity against adenosine diphosphate and adenosine monophosphate.

Nanopore single molecule ATP detection based on the dual effects of specific capturing and signal amplification

Adenosine triphosphate (ATP) plays a crucial role in energy metabolism. Some serious diseases such as Alzheimer’s disease are related to abnormal ATP concentrations. Fast, sensitive, and specific ATP detection is important and challenging in disease diagnosis and biomedical research. In present study, conical nanopore was designed and employed to detect ATP at single molecule level. For overcoming the inherent defects such as non-selectivity and low sensitivity of nanopore in sensing small target molecule, two collaborative improvements of specific identification and signal amplification were proposed. We first used split aptamer capture probes (H1 and S1) to anchor ATP molecule, and then used auxiliary probes (H2 and H3) to form a long-nicked duplex ATP-DNA concatemer by hybridization chain reaction (HCR). Referring ATP-DNA concatemer rather than native ATP to nanopore sensor, characteristic current signals with high signal-to-noise ratio were obtained. By such indirect way, specific and sensitive ATP detection was realized with a linear range from 20 pM to 5 nM and a detection limit of 3.9 pM (S/N = 3). Additionally, the sensor exhibited many merits such as simplify, anti-interference, and especially allowing ATP detection in real sample. So, we believe that the nanopore sensor has good application prospects in screening and management of ATP-related diseases.

Electrochemiluminescent quenching of luminol–doped Zr–MOFs for ATP detection through scavenging ROS using gallic acid–capped Au nanoparticles

In the present study, the highly efficient electrochemiluminescence (ECL) luminophores of Zr-based metal–organic frameworks (MOFs) coordinating with the amino group of luminol (Zr–Lu–MOFs) were developed for fabricating a sensing platform. The ECL emission of a Zr–Lu–MOF/H2O2 system with strong and stable ECL signals was triggered through cyclic voltammetry. Adenosine triphosphate (ATP) was firmly assembled on Zr–Lu–MOF because of the high affinity of Zr4+ toward phosphate groups. ATP was detected using gallic acid (GA)-capped Au (GA@Au) nanoparticles combined with an ATP aptamer. The GA@Au nanoparticles quenched the ECL behavior of the luminol/H2O2 system, and the quenching mechanism was ascribed to the GA scavenging superoxide radical (O2•−) that was generated via the electron redox reaction in H2O2. Under optimal experiments, an ECL biosensor with a linear range of 0.100–1000 nM and a detection limit of 0.0353 nM (S/N = 3) was designed for the selective and sensitive detection of ATP. Thus, the proposed ECL biosensor exhibited good performance with high stability and acceptable fabrication reproducibility, providing a valuable strategy for clinical diagnostics and therapeutics.

A Controlled Release Aptasensor Utilizing AIE-Active MOFs as High-Efficiency ECL Nanoprobe for the Sensitive Detection of Adenosine Triphosphate.

Improving the sensitivity in electrochemiluminescence (ECL) detection systems necessitates the integration of robust ECL luminophores and efficient signal transduction. In this study, we report a novel ECL nanoprobe (Zr-MOF) that exhibits strong and stable emission by incorporating aggregation-induced emission ligands into Zr-based metal-organic frameworks (MOFs). Meanwhile, we designed a high-performance signal modulator through the implementation of a well-designed controlled release system with a self-on/off function. ZnS quantum dots (QDs) encapsulated within the cavities of aminated mesoporous silica nanoparticles (NH2-SiO2) serve as the ECL quenchers, while adenosine triphosphate (ATP) aptamers adsorbed on the surface of NH2-SiO2 through electrostatic interaction act as "gatekeepers." Based on the target-triggered ECL resonance energy transfer between Zr-MOF and ZnS QDs, we establish a coreactant-free ECL aptasensor for the sensitive detection of ATP, achieving an impressive low detection limit of 0.033 nM. This study not only demonstrates the successful combination of ECL with controlled release strategies but also opens new avenues for developing highly efficient MOFs-based ECL systems.

Portable and Recyclable Luminescent Lanthanide Coordination Polymer Film Sensors for Adenosine Triphosphate in Urine.

Adenosine triphosphate (ATP) is a small molecule that is released to the urine from bladder urothelial cells and the bladder mucosal band of the human body. In certain cases, ATP can serve as a biomarker in bladder disease. For the practical applicability of luminescent sensors for ATP in urine, it is significant to find a new strategy for making the detection progress simple and available for in-field urine analysis. Here, a novel luminescent lanthanide coordination polymer (Tb-BPA) was designed and synthesized for quick and sensitive detection of ATP through luminescence quenching with a quenching constant of 4.90 × 103 M-1 and a detection limit of 0.55 × 10-6 M. Besides, Tb-BPA has excellent anti-interference ability and can detect ATP in simulated urine with a small relative standard deviation (<4%). Moreover, the luminescent polyacrylonitrile nanofiber films modified by Tb-BPA were prepared by electrospinning and were used for ATP visual detection. Notably, this film is easy to recover and reuse, and maintains good detection performance after at least 7 cycles.

DNAzyme-mediated fluorescence signal variation of DNA-Ag nanoclusters and construction of an aptasensor for ATP.

DNA-templated silver nanoclusters (DNA-AgNCs) are novel nanomaterials with unique fluorescence characteristics. DNAzyme is a functional oligonucleotide that can catalyze the disruption of nucleic acid substrates. In this research, the effect of DNAzyme digestion on the fluorescence property of DNA-AgNCs was explored for the first time. A significant reduction in the fluorescence intensity of DNA-AgNCs after cleavage by DNAzyme was discovered. Further research found that the DNAzyme-catalyzed cleavage reduced the stability of DNA-AgNCs and led to their aggregation, accounting for a decline in fluorescence intensity up to 84%. Inspired by the above finding, a fluorescent aptasensor that integrates the benefits of DNA-AgNCs, exonuclease III (Exo III)-assisted signal amplification and DNAzyme was developed for sensitive detection of adenosine triphosphate (ATP). Under optimal conditions, the linear range was from 25 μM to 1000 μM and the detection limit was estimated to be 4.46 μM. Furthermore, this fluorescent aptasensor was effectively employed to quantify ATP levels in human serum samples, demonstrating its practicality in detecting ATP in biological matrices. The elucidation of DNAzyme-based fluorescence characteristic variation of DNA-AgNCs may provide insights into the interactions between DNAzyme and nanomaterials and has great prospects in the construction of fluorescent biosensors.

SERS Immunoassay Based on an Enzyme-Catalyzed Cascade Reaction and Metal-Organic Framework/Alkaline Phosphatase for Ultrasensitive Detection of Adenosine Triphosphate.

Herein, an adenosine triphosphate (ATP)-induced enzyme-catalyzed cascade reaction system based on metal-organic framework/alkaline phosphatase (MOF/ALP) nanocomposites was designed to establish a surface-enhanced Raman spectroscopy (SERS) biosensor for use in rapid, sensitive ATP detection. Numerous ALP molecules were first encapsulated using ZIF-90 to temporarily deactivate the enzyme activity, similar to a lock. Au nanostars (AuNSs), as SERS-enhancing substrates, were combined with o-phenylenediamine (OPD) to form AuNSs@OPD, which could significantly improve the Raman signal of OPD. When the target ATP interacted with the MOF/ALP nanocomposites, ATP could act as a key to open the MOF structure, releasing ALP, which should further catalyze the conversion of OPD to oxOPD with the aid of ascorbic acid 2-phosphate. Therefore, with the increasing concentrations of ATP, more ALP was released to catalyze the conversion of OPD, resulting in the reduced intensity of the Raman peak at 1262 cm-1, corresponding to the level of OPD. Based on this principle, the ATP-induced enzyme-catalyzed cascade reaction SERS biosensor enabled the ultrasensitive detection of ATP, with a low detection limit of 0.075 pM. Consequently, this study provides a novel strategy for use in the ultrasensitive, rapid detection of ATP, which displays considerable potential for application in the fields of biomedicine and disease diagnosis.

Enzyme-indole Pyrazole-capped SeNPs based Electrochemical Biosensor for Sensitive Detection of Adenosine Triphosphate

Abstract: In this study, an electrochemical biosensor for the indirect detection of Adenosine triphosphate (ATP) was developed, which was based on the immobilization of the multiwalled carbon nanotubes (MWCNTs) decorated with pyrazole-capped selenium nanoparticles (TRPIDC-CH3 SeNPs) and dual enzyme reaction (hexokinase and glucose oxidase) onto the surface of a bare glassy carbon electrode (GCE) as a working electrode. As confirmed byUltraviolet–visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR) and High-resolution electron microscope (HRTEM), the TRPIDC-CH3 SeNPs successfully green synthesised using Allium sativum cloves and indole pyrazole ligand. The electrochemical study of ATP was performed using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques on a modified electrode for indirect detection of ATP where the required strong electroactive was [Fe(CN)6]3-/4-. The phosphate buffer solution (PBS; 0.1 M) was used as a supporting electrolyte at pH 7 containing 1 mM K4[Fe(CN)6]/K3[Fe(CN)6] as the redox probe operated at an average potential of 0.23 V. The electrochemical enzymic biosensor showed outstanding sensitivity, good stability, and satisfactory reproducibility with an average RSD of 2.30%. The ATP was quantifiable in spiked tablets with a limit of detection (LOD) of 0.015 mM and a limit of quantification (LOQ) of 0,050 mM.

Cu2+-mediated turn-on fluorescence biosensor based on DNA-templated silver nanoclusters for label-free and sensitive detection of adenosine triphosphate

ACu2+-mediated turn-on fluorescence biosensor based on the DNA-templated green-emitting silver nanoclusters (DNA@g-AgNCs) was developed for label-free and sensitive detection of adenosine 5'-triphosphate (ATP). Cu2+ was able to quench the bright green fluorescence of DNA@g-AgNCs because of the coordination and photoinduced electron transfer between DNA@g-AgNCs and Cu2+. Therefore, a unique and effective fluorescence biosensor can be constructed with the formation of DNA@g-AgNCs/Cu2+/ATP ternary-competition system. With the introduction of ATP, theDNA@g-AgNCs/Cu2+ fluorescence sensing system will be disrupted and the fluorescence of DNA@g-AgNCs was recovered due to higher affinity of ATP towards Cu2+. On the basis of this feature, the DNA@g-AgNCs/Cu2+ fluorescence sensing system demonstrated quantitative determinationof ATP in the range 0.05- 3μM and adetection limit of16nM. Moreover, the fluorescence sensing system was successfully applied to the quantitative determination of ATP in human urine and serum samples with recoveries ranging from 98.6 to 106.5%, showing great promise to provide a label-free, cost-efficient, and rapid platform for ATP-related clinical disease diagnosis.

Total Bioaerosol Detection by Split Aptamer-Based Electrochemical Nanosensor Chips.

Bioaerosols could carry and spread harmful microorganisms, thus posing a continuous threat to human beings and livestock health. Early warning and management are crucial for controlling the spread of bioaerosols. Herein, we developed a split aptamer (SA)-based electrochemical nanosensor chip (denoted SAE-nChip) for rapid and sensitive detection of adenosine triphosphate (ATP) in bioaerosols. The platform features two components: split DNA aptamers for their ability to bind ATP and undergo target-induced assembly on the chip surface and ZIF-8@MXene composites for their ability to provide a high surface density of aptamer-binding sites and facilitate the electron transfer at the biointerface. The SAE-nChip was capable of detecting ATP with a detection limit of 10 pM. Furthermore, this assay allowed the detection of ATP in cultured microorganisms and collected real bioaerosols. Overall, this strategy of interfacing DNA aptamers with MXene-based composite materials represents a versatile approach for the ubiquitous detection of biochemical targets in bioaerosols.

Enzyme-embedded ZIF-8/DNA nanocomposite probe for live cells imaging and sensitive detection of ATP

Adenosine triphosphate (ATP) is the direct supplier of energy in almost all biological processes. The intracellular imaging and sensitive detection of ATP will conduce to elucidate its underlying molecular mechanisms of physiological and pathological functions. Herein, a nanocomposite probe was constructed by adsorbing functionalized DNA onto the surface of ZIF-8 pre-embedded with DNA polymerases and nicking endonuclease for live cells imaging and sensitive detection of ATP. The functionalized DNA contained the molecular beacon and recognition probe which with an aptamer sequence, two cleavage sites of nicking enzyme and two template sequences. After uptake into cells, the nanocomposite probe was biodegraded in acid lysosome, releasing the embedded enzymes and surface-adsorbed functionalized DNA. The specific binding of recognition probe to ATP triggered the double-cycle cascade polymerization nicking reaction with the assistance of embedded enzymes, bringing a significant enhancement of fluorescence signal. Based on this, the imaging of ATP in human cancer cells (HeLa, A549 and MCF-7 cells) was successfully implemented. The expression level changes of ATP induced by oligomycin or Ca2+ in HeLa cells could also be efficiently monitored. Furthermore, the sensitive quantification detection of ATP in vitro was achieved with a limit of detection of 7.7 nM. These results showed this enzyme-embedded ZIF-8/DNA nanocomposite probe will be a promising tool for ATP-associated biomedical research.

Porous Fe3O4@COF-Immobilized gold nanoparticles with excellent catalytic performance for sensitive electrochemical detection of ATP

In this work, a “signal-off” electrochemical biosensor was established for sensitive detection of adenosine triphosphate (ATP) based on Fe3O4@covalent organic framework-immobilized gold nanoparticles (Fe3O4@COF–Au NPs) porous composite material as a nanocarrier. The proposed Fe3O4@COF–Au NPs could effectively confine Au NPs in the uniform channels of the Fe3O4@COF, which successfully avoided Au NPs aggregation to a certain extent and provided a comparatively independent and stable micro-environment via its hydrophobic porous nanochannels, thereby owning excellent electro-catalytic performance for the reduction of 4-nitrophenol. Moreover, the Fe3O4@COF–Au NPs nanomaterials were served as functional platform for immobilizing DNA substrate (S0), which was used to bind with the conversion product (S1) of the target ATP for subsequent branched hybridization chain reaction (b-HCR) to form dendritic DNA strands to hinder electron transfer between Fe3O4@COF–Au NPs and 4-nitrophenol, finally achieving sensitive detection of ATP with a wide linear range of 5 pM–50 μM and a low detection limit of 1.6 pM. Such strategy provides a multifunctional immobilized platform for the sensitive detection of ATP and a versatile strategy for monitoring other biomolecules.

A magnified aptamer fluorescence sensor based on the metal organic frameworks adsorbed DNA with enzyme catalysis amplification for ultra-sensitive determination of ATP and its logic gate operation

With the development of frame materials, metal organic frameworks (MOFs) have been successfully applied in the fields of biological small molecule analysis and fluorescent DNA detection. In this work, in view of the good adsorption characteristics of MIL-101(Cr), the highly sensitive detection of adenosine triphosphate (ATP) assisted nucleic acid exonuclease amplification by MIL-101(Cr) on the different affinity of single stranded DNA and double stranded DNA was investigated. The detection limit of ATP reaches 1.7 μM, and the platform has good applicability in biological samples. On this basis, an “AND” logic gate was successfully constructed. Superior sensitivity to ATP in the presence of exonuclease was reflected, which greatly enhanced the system’s fluorescence. Importantly, the fluorescence sensing application of this nanomaterial inspired other target detection and enriched the building blocks of fluorescence sensing platform.

An antifouling electrochemical aptasensor based on poly (glutamic acid) and peptide for the sensitive detection of adenosine triphosphate

A sensitive and antifouling electrochemical aptasensor based on L-Glutamic acid (L-Glu) and peptides was constructed for the detection of adenosine triphosphate (ATP). Firstly, poly L-Glu (p-L-Glu) as the substrate material was directly grown on glass carbon electrode (GCE) via facile and controllable electrodeposition method. Subsequently, the ATP aptamer and peptides were immobilized on the modified electrode, respectively. The prepared aptasensor exhibited a wide linear range of 0.01 pM-1.0 μM, a low LOD of 0.01 pM. The aptasensor also had excellent selectivity, reproducibility and stability. Moreover, due to the synergistic effect of the p-L-Glu and peptides, the aptasensor had the same linear range towards ATP in 10% serum solutions as in ultrapure water, indicating its potential for clinical analysis.

Lateral flow biosensor for universal detection of various targets based on hybridization chain reaction amplification strategy with pregnancy test strip

Abstract Pregnancy test strip is currently one of the most mature and widely used biomedical test products. In this study, based on its simplicity and rapidity, the detecting target-human chorionic gonadotropin (hCG) is coupled with different hybridization probes, while the aptamer is linked with the initiator used for hybridization chain reaction (HCR), which can construct a signal amplification platform based on HCR. The method converts the detection of other biochemical molecules into the detection of hCG signal, and combines the magnetic separation technology to realize the detection of various targets with pregnancy test strip. The rapid quantitative detection can be achieved with smartphone App and portable detection device. Under the optimal experiment conditions, the method can realize rapid and sensitive detection of adenosine triphosphate, thrombin, carcinoembryonic antigen and DNA fragment in human serum, and the visual detection limits can reach 100 pM, 0.2 pM, 5 ng/mL and 5 pM, respectively. The design has low cost, simple operation, and good sensitivity and selectivity for target detection. Based on this design, the detection of multiple analytes can be implemented with different aptamer sequences, thereby broadening the application of commercial pregnancy test strip in the biomedical testing field.

A label-free logic gate hairpin aptasensor for sensitive detection of ATP based on graphene oxide and PicoGreen dye

BackgroundIn this paper, a simple, enzyme-free, label-free fluorescence, high sensitivity logic gate hairpin aptasensor was developed for adenosine triphosphate (ATP) detection based on graphene oxide (GO) and PicoGreen dye.MethodsUsing single-strand deoxyribonucleic acid (DNA) and adenosine triphosphate (ATP) as input signal and fluorescence signal as output signal, if single-strand DNA (DNA-L), single-strand DNA (DNA-S), and ATP were present at the same time, one segment of DNA-L formed a hairpin ring with ATP, and the other segment of DNA-L formed a completely complementary hairpin stem with DNA-S. The hairpin DNA was detached from the GO surface, and PicoGreen dye was embedded into the hairpin stem, and the fluorescence signal was enhanced. The molecular logic gate was constructed through the establishment of logic histogram, logic circuit, truth table, and logic formula. The biosensor-related performances including sensitivity, selectivity, and linearity were investigated, respectively.ResultsWe have successfully constructed a AND logic gate. The detection limit of ATP is 138.0 pmol/L (3σ/slope) with detection range of 50–500 nmol/L (R2 = 0.98951), and its sensitivity is 4.748 × 106–6.875 × 108 a.u. (mol/L)−1.ConclusionsThe logic gate hairpin aptamer sensor has the advantages of high sensitivity, low detection limit, and low cost, and can be successfully applied to the detection of adenosine triphosphate (ATP) in actual human urine samples.

Direct-readout photoelectrochemical lab-on-paper biosensing platform based on coupled electricity generating system and paper supercapacitors

A direct-readout photoelectrochemical (PEC) lab-on-paper device based on coupled an electricity generating system and paper supercapacitors was established for highly sensitive detection of adenosine triphosphate (ATP). Concretely, CdSe quantum dots (QDs) decorated ZnO networks assembled sensing surface provided outstanding photoelectric properties, on which glucose oxidase (GOx) labeled aptamer was subsequently immobilized via the hybridization chain reaction. With analytes present, specific recognition was stimulated by aptamer, resulting in labeled GOx released. Such released GOx could flow to electrochemical cell to conduct electrochemical redox reactions, which could effectively produce electricity that was stored by capacitor I. Sequentially, photoactive material produced an outstanding voltage due to the decrease of steric hindrance on the sensing interface, which was utilized for charging an external capacitor II. The two instantaneous current was acquired along with the discharge of capacitor I and II by digital multimeter (DMM) readout, respectively. The summational current values performed an increment in pace with the addition of target ATP concentration with the dynamic working range from 10 nM to 3 μM and a detection limit of 6.3 nM attained. Significantly, the signal amplified strategy utilizing as-generated electricity from electrochemical redox reactions were isolated from the photoelectrodes, which was beneficial for amplifying the signal response in the PEC matrices and the development of more efficient signal performance.

Luminescent silver nanoclusters for efficient detection of adenosine triphosphate in a wide range of pH values

In this work, polymethacrylic acid (PMAA)-templated silver nanoclusters (Ag NCs) were developed as the fluorescent probe for the efficient and sensitive detection of adenosine triphosphate (ATP) in a wide range of pH values. The fluorescence intensity of the Ag NCs could keep stable with pH values ranging from 2.5 to 9.3. The detection of ATP was based on the quenching of the fluorescent Ag NCs in the presence of ATP. The fluorescence quenching of the Ag NCs with increasing ATP concentration was studied at pH 2.5, 4.5, 7.0 and 8.5 which involved a wide pH environment in body fluids. The limit of detection (LOD) for ATP was as low as 0.1 mmol/L in an acidic environment with pH of 2.5 and all the linear correlation coefficients were satisfactory under wide-span pH values from 2.5 to 8.5. In addition, the sensitive determination of ATP was also achieved by adding copper ions (Cu2+). The high selectivity and rapid detection process proved that the fluorescent probe had great potential to detect ATP in biological samples under different pH conditions.

One-step and ultrasensitive ATP detection by using positively charged nano-gold@graphene oxide as a versatile nanocomposite.

A versatile nanocomposite was simply prepared based upon the electrostatic adsorption of positively charged gold nanoparticles with negatively charged graphene oxide (nano-gold@GO), and utilized as a novel fluorescence quenching platform for ultrasensitive detection of adenosine triphosphate (ATP). In the designed system, DNA-stabilized Ag nanoclusters (DNA/AgNCs) were used as fluorescent probes, DNA duplex was formed in the presence of ATP, and they can electrostatically adsorb onto the surface of nano-gold@GO to quench the fluorescence signal. Upon the addition of exonuclease III (Exo III), the DNA duplex would be hydrolyzed into DNA fragments and resulted in the recovery of the fluorescence signals due to the diffusion of AgNCs away from nano-gold@GO. Based on these, sensitive detection of ATP was realized with a detection range of 5.0pM-20nM. Notably, a good recovery in the range of 94-104% was obtained when detecting ATP in human serum samples, indicating a promising application value in early disease diagnosis. Graphical abstract A functional positively charged nano-gold@graphene oxide was fabricated and utilized as an enhanced fluorescence quenching platform for the detection of ATP, coupled with exonuclease III-assisted signal amplification.