- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A Label-Free Fluorescent DNA Calculator Based on Gold Nanoparticles for Sensitive Detection of ATP
摘要： Herein we described a deoxyribonucleic acid (DNA) calculator for sensitive detection of the determination of adenosine triphosphate (ATP) using gold nanoparticles (GNP) and PicoGreen fluorescence dye as signal transducer, and ATP and single-stranded DNA (DNA-M') as activators. The calculator-related performances including linearity, reaction time, logic gate, and selectivity were investigated, respectively. The results revealed that this oligonucleotide sensor was highly sensitive and selective. The detection range was 50–500 nmol/L (R2 = 0.99391) and the detection limit was 46.5 nmol/L. The AND DNA calculator was successfully used for the ATP detection in human urine. Compared with other methods, this DNA calculator has the characteristics of being label-free, non-enzymic, simple, and highly sensitive.
关键词： DNA calculator,enzyme-free,gold nanoparticles,label-free fluorescence,ATP detection
更新于2025-11-19 16:46:39
-
Amplified visual immunosensor integrated with nanozyme for ultrasensitive detection of avian influenza virus
摘要： Nanomaterial-based artificial enzymes or nanozymes exhibit superior properties such as stability, cost effectiveness and ease of preparation in comparison to conventional enzymes. However, the lower catalytic activity of nanozymes limits their sensitivity and thereby practical applications in the bioanalytical field. To overcome this drawback, herein we propose a very simple but highly sensitive, specific and low-cost dual enhanced colorimetric immunoassay for avian influenza A (H5N1) virus. 3,3′,5,5′- Tetramethylbenzidine (TMBZ) was used as a reducing agent to produce gold nanoparticles (Au NPs) with blue colored solution from a viral target-specific antibody-gold ion mixture at first step. The developed blue color from the sensing design was further amplified through catalytic activity of Au NPs in presence of TMBZ–hydrogen peroxide (H2O2) solution in second step. Hence, the developed dual enhanced colorimetric immunosensor enables the detection of avian influenza virus A (H5N1) with a limit of detection (LOD) of 1.11 pg/mL. Our results confirmed that the developed assay has superior sensitivity than the conventional ELISA method, plasmonic-based bioassay and commercial flu diagnostic kits. Proposed sensing method further showed its capability to detect viruses, avian influenza A (H4N6) and A (H9N2) virus, in blood samples with limit of detection of 0.0269 HAU and 0.0331 HAU respectively.
关键词： Peroxidase mimic,Dual color enhancement,Gold nanoparticles,Avian influenza virus detection
更新于2025-11-14 17:04:02
-
Non-enzymatic sensing of dopamine by localized surface plasmon resonance using carbon dots-functionalized gold nanoparticles
摘要： A highly selective, sensitive, and rapid colorimetric sensor for the determination of dopamine (DA) was developed using the color change of S-doped carbon dots functionalized gold nanoparticles (S-CDs@Au NPs). The base of the method is the formation of a complex between the amine groups of dopamine with carboxylic groups of S-CDs@Au NPs followed by their aggregation with Fe3+ ions which acts as the linkers causing a red shift from 520 to 670 nm in the localized surface plasmon peak of S-CDs@Au NPs. The ratio of absorbance intensity at 670 nm to 520 nm was monitored as the analytical signal for determination of dopamine. The parameters affecting the analytical signal including reaction time, solution pH, the concentration of Au NPs and concentration of Fe3+ were optimized. At optimized conditions, the calibration curve was linear in the concentration range of 0.81-16.80 μM of dopamine. The detection and quantification limits were 0.23 μM and 0.77 μM, respectively. The intra-day and inter-day relative standard deviation (RSDs) at 5.0 μM of DA were 3.9% and 5.6%, respectively (n = 5). The applicability of the method for determination of DA in dopamine ampoule, urine and serum human samples was investigated.
关键词： Carbon dots,Localized surface plasmon resonance,Colorimetric chemical sensor,Dopamine,Gold nanoparticles
更新于2025-11-14 15:18:02
-
Surface Plasmon Resonance Enhancement of PbS Quantum Dot-Sensitized Solar Cells
摘要： Lead sulfide (PbS)-sensitized quantum dot solar cells (QDSC) were fabricated using TiO2 and TiO2–Au plasmonic nanocomposite films by successive ionic layer adsorption and reaction (SILAR) method. The average size of gold nanoparticles (GNPs) used for fabricating nanocomposite films was ~ 15 nm. Thin plasmonic QDSC, with a film thickness of 10 μm, showed an increase of ~ 11% in photocurrent and ~ 6% in overall energy conversion efficiency compared to the device without GNPs. The improved performance of QDSCs is attributed to the increased absorption due to the plasmonic near-field effects of the incorporated GNPs. High-efficiency PbS/CdS-co-sensitized thick cells with 16 μm bilayer TiO2 also showed improvement in photocurrent and efficiency. The results show that the plasmonic-enhanced absorption can be used to augment efficiency of QDSC devices in much the same fashion as that of dye-sensitized solar cells.
关键词： Gold nanoparticles,Quantum dot-sensitized solar cells,Plasmonics,Photovoltaics
更新于2025-10-22 19:40:53
-
Gold nanoparticles of different shape for bicolor lateral flow test
摘要： Spherical gold nanoparticles are the most commonly used marker in lateral flow assays. However, the widespread practice of using identical coloration for the test and control zones of test strips can lead to erroneous interpretations of the assay’s results. We propose an immunochromatographic test strip with lines of different colors. For this purpose, gold nanoparticles of different shapes were used, namely blue nanoflowers in the test zone and red gold nanospheres in the control zone. A detailed synthesis procedure for nanoparticles and their conjugates is considered and design parameters for optimal results are described. For the first time, nanoparticles of different shapes have been combined in the test strip with indirect labeling of specific antibodies (via their interaction with labeled secondary antibodies). Using the T-2 toxin (T2T) as an example, an instrumental detection limit of 30 pg/mL and a working range 0.06-0.9 ng/mL were achieved in an analysis of water-organic corn extracts.
关键词： gold nanoparticles,Immunochromatography,test strip,mycotoxin,indirect labeling,gold nanoflowers
更新于2025-09-23 15:23:52
-
Surface chemical states of gold nanoparticles prepared using the solution-plasma method in a CsCl aqueous solution
摘要： In this study, gold nanoparticles (AuNPs) prepared in a 5 mM CsCl aqueous solution using the solution‐plasma method are characterized via transmission electron microscopy (TEM) and X‐ray photoelectron spectroscopy with synchrotron radiation (SR‐XPS). The particle diameter is measured over the process time via TEM. During the solution‐plasma process, small particles of 2.1 to 2.2‐nm diameter are generated in the CsCl aqueous solution; these particles then enlarge via Ostwald ripening over time until they reach an equilibrium size of ~13 nm after 36 days. In addition, the surface chemical states of the AuNPs are characterized at different depths via SR‐XPS. The SR‐XPS measurements obtained using incident X‐ray energy (hν) of 945.0 eV revealed that Cs─Au, Cl─Au, and Cs─Cl─Au bonds are present 1.2 nm below the surface. The measurements obtained at an incident X‐ray energy of 2515.0 eV showed that Cs─Cl─Au bonding is also present 2.5 nm below the surface, indicating that Cs and Cl strongly interact with Au. The TEM and SR‐XPS measurements revealed that 2 processes occur cyclically during the growth process via Ostwald ripening: (i) the Cs and Cl in the aqueous solution adsorb on the AuNP surface and (ii) Au atoms subsequently bond to the AuNPs surface.
关键词： solution‐plasma method,TEM,gold nanoparticles,XPS,surface chemical states
更新于2025-09-23 15:23:52
-
A Simple Colorimetric and Fluorescent Sensor to Detect Organophosphate Pesticides Based on Adenosine Triphosphate-Modified Gold Nanoparticles
摘要： A simple and dual modal (colorimetric and fluorescent) sensor for organophosphate pesticides with high sensitivity and selectivity using adenosine triphosphate (ATP)- and rhodamine B-modified gold nanoparticles (RB-AuNPs), was successfully fabricated. This detection for ethoprophos afforded colorimetric and fluorescence imaging changes visualization. The quantitative determination was linearly proportional to the amounts of ethoprophos in the range of a micromolar scale (4.0–15.0 μM). The limit of detection for ethoprophos was as low as 37.0 nM at 3σ/k. Moreover, the extent application of this simple assay was successfully demonstrated in tap water samples with high reliability and applicability, indicating remarkable application in real samples.
关键词： multimodal assay,ethoprophos detection,gold nanoparticles,colorimetric and fluorescent sensor,organophosphate pesticides
更新于2025-09-23 15:23:52
-
Gold Nanoparticles-embedded MAPbI3 Perovskite Thin Films
摘要： We synthesized the gold nanoparticles (Au NPs)-embedded methylammonium lead iodide (MAPbI3) film for the first time. The effects of metal nanoparticles on MAPbI3 perovskite were systematically studied using UV-Vis absorption and photoluminescence (PL) measurements. As a result, the 20-nm-sized Au NPs-embedded MAPbI3 film exhibited a 4.15% higher absorbance than the bare MAPbI3 film. Moreover, the average PL intensity of the Au NPs-embedded MAPbI3 film increased by about 75.25% over the bare MAPbI3 film. Therefore, we have confirmed that addition of the Au NPs has a positive effect on the optical properties of MAPbI3, and we believe that this study will provide a basic insight into the metal nanoparticles-embedded perovskite thin films for the future optoelectronic applications.
关键词： Perovskite,Photoluminescence,Gold nanoparticles
更新于2025-09-23 15:23:52
-
Construction of a Biosensor Based on a Combination of Cytochrome c, Graphene, and Gold Nanoparticles
摘要： A biosensor based on a combination of cytochrome c (Cyt c), electrochemical reduced graphene oxides (ERGO), and gold nanoparticles (AuNPs) on a glassy carbon electrode (GCE) was fabricated. The proposed biosensor electrode was denoted as GCE/ERGO-Na?on/AuNPs/Cyt c/Na?on, where ERGO-Na?on was deposited by dropping graphene oxides-Na?on mixed droplet ?rst and following electrochemical reduction, AuNPs were directly deposited on the surface of the ERGO-Na?on modi?ed electrode by electrochemical reduction, and other components were deposited by the dropping-dry method. The effect of the deposition amount of AuNPs on direct electrochemistry of Cyt c in the proposed electrode was investigated. The hydrogen peroxide was taken to evaluate the performance of the proposed biosensor. The results showed that the biosensor has great analytical performance, including a high sensitivity, a wide linear range, a low detection limit, and good stability, reproducibility, and reliability.
关键词： gold nanoparticles,cytochrome c,graphene,direct electrochemistry,biosensor,hydrogen peroxide
更新于2025-09-23 15:23:52
-
Electrochemiluminescence sensor based on upconversion nanoparticles and oligoaniline-crosslinked gold nanoparticles imprinting recognition sites for the determination of dopamine
摘要： For the determination of dopamine (DA) in serum samples, a quenching-type electrochemiluminescence sensor was constructed in this study. Upconversion nanoparticles (UCNPs) enhanced by covalent organic frameworks (COFs)-based hybrid and oligoaniline-crosslinked gold nanoparticles (AuNPs) imprinting recognition sites were introduced in electrochemiluminescence (ECL) system at first time. The porous COFs-based hybrid with large specific surface area was modified on the electrode firstly to hold more UCNPs and imprinting recognition sites. AuNPs, here, was employed in developed sensor for two objectives: 1) AuNPs on COFs-based hybrid enabled the hybrid to tunnel the electrons, which helped to improve the ECL intensity; 2) AuNPs-based thioaniline units (PATP@AuNPs) electropolymerized on the electrode in the presence of template to form oligoaniline-crosslinked AuNPs matrix. Then the exclusion of template from matrix yielded molecularly three-dimensional imprinted contours with conductivity, conducive to specific recognition and further amplify the ECL. The double recognition mode in this work involves the recognition effect of imprinted contours and quenching effect of o-benzoquinone species. The quantum chemical calculation was performed to analyzing the possible recognition and binding mechanisms of molecularly three-dimensional imprinted contours. The results showed imprinted contours could bind the target by complementary spatial cavities and weak interactions. The proposed approach yields a wide detection range (10-14-10-6 M), low limit of detection (LOD=2×10-15 M) and acceptable recoveries (93.25%-112.97%) in rat serum sample, demonstrating that the developed method holds great promise to be applied to DA detection in practical samples.
关键词： Electroconductibility molecular imprinting polymer,Covalent organic frameworks,Oligoaniline-crosslinked gold nanoparticles,Dopamine,Electrochemiluminescence
更新于2025-09-23 15:23:52