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1.
J Am Chem Soc ; 146(6): 4260-4269, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38305175

RESUMO

Quantum tunneling, a phenomenon that allows particles to pass through potential barriers, can play a critical role in energy transfer processes. Here, we demonstrate that the proper design of organic-inorganic interfaces in two-dimensional (2D) hybrid perovskites allows for efficient triplet energy transfer (TET), where quantum tunneling of the excitons is the key driving force. By employing temperature-dependent and time-resolved photoluminescence and pump-probe spectroscopy techniques, we establish that triplet excitons can transfer from the inorganic lead-iodide sublattices to the pyrene ligands with rapid and weakly temperature-dependent characteristic times of approximately 50 ps. The energy transfer rates obtained based on the Marcus theory and first-principles calculations show good agreement with the experiments, indicating that the efficient tunneling of triplet excitons within the Marcus-inverted regime is facilitated by high-frequency molecular vibrations. These findings offer valuable insights into how one can effectively manipulate the energy landscape in 2D hybrid perovskites for energy transfer and the creation of diverse excitonic states.

2.
Langmuir ; 40(11): 5753-5763, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38436581

RESUMO

With four nanoparticles as the nanomatrix, dinotefuran (DNF) as the template molecule, N-isopropylacrylamide as the functional monomer, trimethylolpropane and trimethacrylate as the cross-linker, four nanosurface molecularly imprinted polymer (MIP) bifunctional probes were prepared by microwave synthesis. It was found that palladium nanosurface MIP (Pd@MIP) not only recognized DNF but also had the strongest catalytic effect on the new nanogold indicator reaction of acrylic acid-HAuCl4, which was evaluated quickly with the slope procedure developed by us. The generated gold nanoparticles (AuNPs) not only possessed the resonance Rayleigh scattering (RRS) effect but also strong surface-enhanced Raman scattering (SERS) activity. The combination of Pd@MIP with DNF enhanced the catalytic effect by coupling the nanosurface electrons with π-electrons, thus enhancing both scattering signals. A new Pd@MIP nanoprobe catalytic-SERS/RRS dual-mode analytical platform was developed for the specific and sensitive detection of DNF. The linear ranges of the SERS and RRS methods were 0.075-0.75 and 0.1-0.75 nmol/L, and the limits of detection were 0.03 and 0.06 nmol/L, respectively. The standard deviations were 0.54-2.39%, and the recoveries were 93-105%.

3.
Analyst ; 149(11): 3236-3244, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38687011

RESUMO

In this work, a nanogold surface molecularly imprinted polymer spectral probe (AuNP@MIP) for selectively identifying ferrocyanide was prepared under microwave irradiation using nanogold as the core, ferrocyanide as the template ion, methacrylic acid as the monomer, and ethylene glycol dimethacrylate as the cross-linking agent. AuNP@MIP was found to produce a resonance Rayleigh scattering (RRS) peak at 370 nm. When potassium ferrocyanide (K4Fe(CN)6) was present, a AuNP@MIP-Fe(CN)6 complex was formed, producing RRS-energy transfer (RRS-ET). With an increase in ferrocyanide concentration within a certain range, the RRS intensity at 370 nm decreased linearly, and the detection range was 0.02-0.40 µmol L-1, with a detection limit as low as 0.006 µmol L-1 ferrocyanide. This new method has the advantages of simplicity, rapidity, and selectivity when applied for the determination of K4Fe(CN)6 in table salt.

4.
Analyst ; 149(8): 2374-2387, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38456248

RESUMO

A new coinage metal nanocluster surface molecularly imprinted polymethacrylic acid nanoprobe (NC@MIP) for the selective determination of 2,4,6-trichlorophenol (TCP) was prepared via microwave synthesis using 2,4,6-trichlorophenol as a template molecule, copper nanoclusters (CuNC) as a nanosubstrate, and methacrylic acid as a polymer monomer. It was found that the copper nanocluster MIP (CuNC@MIP) shows the strongest catalytic performance for the reduction of HAuCl4 by hydrazine hydrate for the on-site generation of gold nanoparticles (AuNPs) with the surface plasmon resonance (SPR) effects of resonance surface-enhanced Raman scattering (SERS) and resonance Rayleigh scattering (RRS) as well as absorption (Abs). When TCP was added, the CuNC@MIP nanoprobe and TCP-formed CuNC@MIP-TCP nanoenzyme with stronger catalytic activity generated more AuNPs, and the trimodal analytical signal was enhanced linearly. Therefore, a new SERS/RRS/Abs trimodal sensing platform for TCP was constructed, which was simple, rapid, sensitive, and selective. For each mode, the linear ranges were 0.0075-0.075, 0.010-0.10, and 0.010-0.10 nmol L-1, and the detection limits were 0.0010, 0.021, and 0.043 nmol L-1, respectively. The relative deviation of TCP in different water quality was 0.47%-2.5% and the recovery rate was 94.6%-108.6%.

5.
Angew Chem Int Ed Engl ; 63(20): e202403083, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38502273

RESUMO

Dopant-free hole transport materials (HTMs) are ideal materials for highly efficient and stable n-i-p perovskite solar cells (PSCs), but most current design strategies for tailoring the molecular structures of HTMs are limited to single strategy. Herein, four HTMs based on dithienothiophenepyrrole (DTTP) core are devised through dual-strategy methods combining conjugate engineering and side chain engineering. DTTP-ThSO with ester alkyl chain that can form six-membered ring by the S⋅⋅⋅O noncovalent conformation lock with thiophene in the backbone shows good planarity, high-quality film, matching energy level and high hole mobility, as well as strong defect passivation ability. Consequently, a remarkable power conversion efficiency (PCE) of 23.3 % with a nice long-term stability is achieved by dopant-free DTTP-ThSO-based PSCs, representing one of the highest values for un-doped organic HTMs based PSCs. Especially, the fill factor (FF) of 82.3 % is the highest value for dopant-free small molecular HTMs-based n-i-p PSCs to date. Moreover, DTTP-ThSO-based devices have achieved an excellent PCE of 20.9 % in large-area (1.01 cm2) devices. This work clearly elucidates the structure-performance relationships of HTMs and offers a practical dual-strategy approach to designing dopant-free HTMs for high-performance PSCs.

6.
Chemistry ; 29(31): e202300259, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-36912563

RESUMO

Two new pyrimidine-based iridium complexes with triphenylamine and tetraphenylsilane, namely (TPAPr)2 IrAcac and (TPSPr)2 IrAcac, were fully synthesized and characterized. Both of the targeted iridium complexes exhibit excellent thermal stability and high photoluminescence quantum yields. Compared to (TPAPr)2 IrAcac, (TPSPr)2 IrAcac achieved its highest PLQY and current efficiency (CE) at higher dopant concentration probably because of its bulky tetraphenylsilane group, which can effectively suppress the concentration quenching. However, according to DFT studies, (TPSPr)2 IrAcac shows faster non-radiative transitions due to the presence of more excited-state distortions than (TPAPr)2 IrAcac. As a result, Green phosphorescent polymer light-emitting diodes (PLEDs) containing (TPAPr)2 IrAcac and (TPSPr)2 IrAcac as dopants exhibit exceptional device performance with peak CE values of 38.24 and 36.06 cd A-1 , respectively. (TPAPr)2 IrAcac exhibited a superior efficiency than (TPSPr)2 IrAcac because of its high Φp , low RMSD value, and efficient energy transfer from the host to the guest. More importantly, the PLEDs based on (TPAPr)2 IrAcac and (TPSPr)2 IrAcac show stable phosphorescent emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.313, 0.497) and (0.299, 0.483), respectively. This work points out a viable method for creating phosphorescent iridium complexes based on pyrimidine for high-efficiency organic light-emitting diodes (OLEDs).

7.
Int J Mol Sci ; 24(3)2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36769237

RESUMO

Liquid crystals (LCs) are a very important display material. However, the use of LC, especially LC-loaded nanoparticles, as a catalyst to amplify the analytical signal and coupled with specific aptamer (Apt) as a recognition element to construct a highly sensitive and selective three-mode molecular spectral assay is rarely reported. In this article, five LCs, such as cholesteryl benzoate (CB), were studied by molecular spectroscopy to indicate the liquid crystal nanoparticles in the system, and highly catalytic and stable CB loaded-nanosilver (CB@AgNPs) sol was prepared. The slope procedure was used to study the catalysis of the five LCs and CB@AgNPs on the new indicator reaction between AgNO3 and sodium formate (Fo) to produce silver nanoparticles (AgNPs) with a strong surface plasmon resonance absorption (Abs) peak at 450 nm, a resonance Rayleigh scattering (RRS) peak at 370 nm and a surface enhanced Raman scattering (SERS) peak at 1618 cm-1 in the presence of molecular probes. By coupling the new CB@AgNPs catalytic indicator reaction with the Apt reaction, a new CB@AgNPs catalytic amplification-SERS/RRS/Abs trimode biosensoring platform was constructed for detecting inorganic pollutants, such as Pb2+, Cd2+, Hg2+ and As3+.


Assuntos
Técnicas Biossensoriais , Cristais Líquidos , Nanopartículas Metálicas , Chumbo , Nanopartículas Metálicas/química , Prata/química , Oligonucleotídeos , Catálise , Análise Espectral Raman/métodos
8.
Analyst ; 147(11): 2369-2377, 2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35535968

RESUMO

A neodymium metal-organic framework (MOFNd) was prepared using 1H-pyrazole-3,5-dicarboxylic acid (H3pdc) and 2-pyrazinecarboxylic acid as ligands. Through the addition of HAuCl4 as a precursor and NaBH4 as a reducing agent, a new MOFNd-loaded nanogold (AuNPs) (Au@MOFNd) nanosol with good stability and high catalytic activity was conveniently prepared via a solvothermal-reduction method and characterized. It was found that the indicator reaction of reducing HAuCl4 by Na2SO3 to generate AuNPs was slow. Au@MOFNd strongly catalyzes this nanoreaction, and the produced AuNPs exhibit a strong resonance Rayleigh scattering (RRS) peak at 370 nm, and a strong surface-enhanced Raman scattering (SERS) peak at 1617 cm-1 with the addition of the molecular probe Victoria blue 4R (VB4r). A novel SERS/RRS di-mode quantitative analysis method for glyphosate (GLY) was established by coupling this new Au@MOFNd catalytic indicator reaction with the aptamer (Apt) reaction of GLY, with SERS and RRS detection limits of 0.02 nM and 0.3 nM, respectively. It has been applied to the analysis of soil samples with a recovery rate of 93.0%-106.5% and precision of 2.2%-4.1%, and the results were satisfactory.


Assuntos
Ouro , Nanopartículas Metálicas , Catálise , Glicina/análogos & derivados , Oligonucleotídeos , Análise Espectral Raman/métodos , Glifosato
9.
J Am Chem Soc ; 143(37): 15215-15223, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34516736

RESUMO

Controlling grain growth is of great importance in maximizing the charge carrier transport for polycrystalline thin-film electronic devices. The thin-film growth of halide perovskite materials has been manipulated via a number of approaches including solvent engineering, composition engineering, and post-treatment processes. However, none of these methods lead to large-scale atomically flat thin films with extremely large grain size and high charge carrier mobility. Here, we demonstrate a novel π-conjugated ligand design approach for controlling the thin-film nucleation and growth kinetics in two-dimensional (2D) halide perovskites. By extending the π-conjugation and increasing the planarity of the semiconducting ligand, nucleation density can be decreased by more than 5 orders of magnitude. As a result, wafer-scale 2D perovskite thin films with highly ordered crystalline structures and extremely large grain size are readily obtained. We demonstrate high-performance field-effect transistors with hole mobility approaching 10 cm2 V-1 s-1 with ON/OFF current ratios of ∼106 and excellent stability and reproducibility. Our modeling analysis further confirms the origin of enhanced charge transport and field and temperature dependence of the observed mobility, which allows for clear deciphering of the structure-property relationships in these nascent 2D semiconductor systems.

10.
Mikrochim Acta ; 188(5): 175, 2021 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-33893886

RESUMO

Bisphenol A (BPA), as a typical endocrine disruptor, poses a serious threat to human health. Therefore, it is urgent to establish a rapid, sensitive, and simple method for the determination of BPA. In this paper, based on the aptamer-mediated single-atom Fe carbon dot catalyst (SAFe) catalyzing the HAuCl4-ethylene glycol (EG) nanoreaction, a new SERS/RRS di-mode detection method for BPA was established. The results show that SAFe exhibits a strong catalytic effect on the HAuCl4-EG nanoreaction, which could generate purple gold nanoparticles (AuNPs) with resonance Rayleigh scattering (RRS) signals and surface-enhanced Raman scattering (SERS) effects. After the addition of BPA aptamer (Apt), it could encapsulate SAFe through intermolecular interaction, thus inhibiting its catalytic action, resulting in the reduction of AuNPs generated and the decrease of RRS and SERS signals of the system. With the addition of BPA, Apt was specifically combined with BPA, and SAFe was re-released to restore the catalytic ability; the generated AuNPs increased. As a result of this RRS and SERS signals of the system recovered, and their increment was linear with the concentration of BPA. Thus, the quantification of 0.1-4.0 nM (RRS) and 0.1-12.0 nM (SERS) BPA was realized, and the detection limits were 0.08 nM and 0.03 nM, respectively. At the same time, we used molecular spectroscopy and electron microscopy to study the SAFe-HAuCl4-ethylene glycol indicator reaction, and proposed a reasonable SAFe catalytic reaction mechanism. Based on Apt-mediated SAFe catalysis gold nanoreaction amplification, a SERS/RRS di-mode analytical platform was established for targets such as BPA.


Assuntos
Aptâmeros de Nucleotídeos/química , Compostos Benzidrílicos/análise , Disruptores Endócrinos/análise , Poluentes Ambientais/análise , Nanopartículas Metálicas/química , Fenóis/análise , Pontos Quânticos/química , Compostos Benzidrílicos/química , Carbono/química , Catálise , Cloretos/química , Disruptores Endócrinos/química , Poluentes Ambientais/química , Etilenoglicol/química , Ouro/química , Compostos de Ouro/química , Ferro/química , Limite de Detecção , Fenóis/química , Plásticos/análise , Reprodutibilidade dos Testes , Análise Espectral Raman/métodos
11.
Molecules ; 26(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34641474

RESUMO

Using citric acid (CA) and ethylenediamine (EDA) as precursors, stable nitrogen-doped carbon dots (CD) nanosols were prepared by microwave procedure and characterized in detail. It was found that CDNs catalyze ethanol (Et)-HAuCl4 to generate gold nanoparticles (AuNPs), which have strong surface plasmon resonance, Rayleigh scattering, (RRS) and a surface plasmon resonance (SPR) absorption (Abs) effect at 370 nm and 575 nm, respectively. Compled the new catalytic amplification indicator reaction with the specific As3+ aptamer reaction, a new RRS/Abs dual-mode aptamer sensor for the assay of trace As3+ was developed, based on the RRS/Abs signals increasing linearly with As3+ increasing in the ranges of 5-250 nmol/L and 50-250 nmol/L, whose detection limits were 0.8 nmol/L and 3.4 nmol/L As3+, respectively. This analytical method has the advantages of high selectivity, simplicity, and rapidity, and it has been successfully applied to the detection of practical samples.

12.
Angew Chem Int Ed Engl ; 60(15): 8337-8343, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33497510

RESUMO

Metal halide perovskites are promising for applications in light-emitting diodes (LEDs), but still suffer from defects-mediated nonradiative losses, which represent a major efficiency-limiting factor in perovskite-based LEDs (PeLEDs). Reported here is a strategy to synthesize molecular passivators with different anchoring groups for defects passivation. The passivated perovskite thin films exhibit improved optoelectronic properties as well as reduced grain size and surface roughness, thus enable highly efficient PeLEDs with an external quantum efficiency of 15.6 % using an imidazolium terminated passivator. Further demonstrated is that the in situ formation of low-dimensional perovskite phase on the surface of three-dimensional perovskite nanograins is responsible for surface defects passivation, which leads to significantly enhanced device performance. Our results provide new fundamental insights into the role of organic molecular passivators in boosting the performance of PeLEDs.

13.
Analyst ; 144(17): 5090-5097, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31360936

RESUMO

Co-doped carbon dots are new multifunctional carbon nanomaterials. Their fast preparation and new analytical applications such as in continuous detection and resonance Rayleigh scattering (RRS) probes are of interest to people. Herein, the N/Au co-doped carbon dots (CDN/Au) were prepared quickly by a microwave synthesis method using fructose as the carbon source and urea and HAuCl4 as dopants, and it exhibited an excellent RRS effect at 555 nm. Based on both silicate (SiO32-) and phosphate (PO43-) reacting with ammonium molybdate to form silicomolybdate heteropoly acid (SiMo) and phosphomolybdate heteropoly acid (PMo), PMo decomposed by the addition of citric acid, and SiMo/PMo combined with CDN/Au to show good RRS analytical properties, and a new strategy was developed to detect SiO32- and PO43- by the CDN/Au probes continuously. With the increase of SiO32- (PO43-), SiMo (PMo) reacted with CDN/Au probes to form more big particles which resulted in the RRS intensity enhancement at 555 nm, and had a good linear relationship with the SiO32- (PO43-) concentration in the range of 1.11 µg L-1-19.98 µg L-1, with detection limits of 0.3 µg L-1 SiO32- and 0.3 µg L-1 PO43-. Accordingly, a new RRS method was established for continuous detection of SiO32- and PO43- using CDN/Au as the probe.

14.
Mikrochim Acta ; 186(5): 323, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31049706

RESUMO

A fluorometric clenbuterol immunoassay is described that uses S- and N-co-doped carbon quantum dots as the fluorescent probe. Strongly fluorescent S/N-doped carbon quantum dots (S/N-CDs) were synthesized by hydrothermal method using fructose as the carbon precursor and L-cysteine as S/N sources. The S/N-CDs were characterized by transmission electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy (FTIR). Under 350 nm photoexcitation, they display strong purple fluorescence with an emission peak at 405 nm. In pH 4.0 solution, the amino groups (confirmed by FTIR) on the carbon quantum dots were coupled to clenbuterol antibody (Ab) by amine-amine coupling reaction to quench the fluorescence. If clenbuterol (Clen) is added, it binds to the Ab to generate a stable Ab-Clen immunocomplex and free S/N-CD. This causes the fluorescence of nanoprobe to be restored. The fluorescence of the system increases linearly in the 0.07-1.7 ng·mL-1 Clen concentration range. The probe of type S/N4-CD displays the best sensitivity. The detection limit is 23 pg·mL-1. Graphical abstract Schematic presentation of clenbuterol fluorometric immunoassay using sulfur and nitrogen doped carbon quantum dots.


Assuntos
Carbono/química , Clembuterol/análise , Corantes Fluorescentes/química , Imunoensaio/métodos , Nitrogênio/química , Pontos Quânticos/química , Enxofre/química , Técnicas Biossensoriais/métodos , Limite de Detecção , Prata/química , Espectrometria de Fluorescência/métodos
15.
Mikrochim Acta ; 186(9): 638, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31440836

RESUMO

Carbon dots doped with N/Ce, N/Eu and N/Tb were prepared by a microwave based hydrothermal technique. The fluorescence of the N/Ce co-doped carbon dots (CDN/Ce) is strongest. They have excitation/emission maxima at 340/441 nm. CDN/Ce was characterized by scanning electron microscopy, infrared and fluorescence spectroscopy. On addition of the nucleic acid aptamer (Apt) against arsenic(III) in pH 7 solution, the blue fluorescence of the doped carbon dots is partially quenched due to electrostatic interaction. On addition of As(III), it will bind to the aptamer, and the carbon dots are released. Hence, fluorescence becomes gradually restored. In addition, the resonance Rayleigh scattering signal (measured at 340 nm) is reduced. This dual-mode assay works in the 0.5-5.8 µg·L-1 As(III) concentration range and has a 0.2 µg·L-1 detection limit. Graphical abstract Schematic representation of fluorometric and resonance Rayleigh scattering dual mode analysis of As3+ by using coupled Apt and CDN/Ce probes. Apt: Aptamer. CD: Carbon dot. Flu: Fluorescence. RRS: Resonance Rayleigh scattering.

16.
Luminescence ; 33(6): 1033-1039, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29900660

RESUMO

The nanogold reaction between HAuCl4 and trisodium citrate (TCA) proceeded very slowly at 60°C in a water bath. The as-prepared graphene oxide nanoribbons (GONRs) exhibited strong catalysis during the reaction to form gold nanoparticles (Au NPs) and appeared as a strong surface-enhanced Raman scattering (SERS) peak at 1616 cm-1 in the presence of the molecular probe Victoria blue 4R (VB4r). With increase in GONR concentration, the SERS peak increased due to increased formation of Au NPs. Upon addition of dimethylglyoxime (DMG) ligand, which was adsorbed onto the GONR surface to inhibit GONR catalysis, the SERS peak decreased. When Ni2+ was added, a coordination reaction between DMG and Ni2+ took place to form stable complexes of [Ni (DMG)2 ]2+ and the release of free GONR catalyst that resulted in the SERS peak increasing linearly. A SERS quantitative analysis method for Ni2+ was therefore established, with a linear range of 0.07-2.8 µM, and a detection limit of 0.036 µM Ni2+ .


Assuntos
Ouro/química , Grafite/química , Nanoestruturas/química , Níquel/análise , Óxidos/química , Oximas/química , Catálise , Análise Espectral Raman , Propriedades de Superfície
17.
Luminescence ; 33(1): 131-137, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28799722

RESUMO

Using silver nanoparticles (AgNPs) as the nanocatalyst, l-cysteine rapidly reduced HAuCl4 to make a stable gold nanoparticle sol (Ag/AuNP) that had a high surface-enhanced Raman scattering (SERS) activity in the presence of Victoria blue 4R (VB4r) molecular probes. Under the selected conditions, chondroitin sulfate (Chs) reacted with the VB4r probes to form associated complexes that caused the SERS effect to decrease to 1618 cm-1 . The decreased SERS intensity was linear to the Chs concentration in the range 3.1-500 ng/ml, with a detection limit of 1.0 ng/ml Chs. Accordingly, we established a simple and sensitive SERS quantitative analysis method to determine Chs in real samples, with a relative standard deviation of 1.47-3.16% and a recovery rate of 97.6-104.2%.


Assuntos
Sulfatos de Condroitina/análise , Ouro/química , Nanopartículas Metálicas/química , Sondas Moleculares/química , Corantes de Rosanilina/química , Tamanho da Partícula , Análise Espectral Raman , Propriedades de Superfície
18.
Luminescence ; 33(6): 1113-1121, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30014561

RESUMO

The as-prepared graphene oxide (GO) exhibited a strong catalytic effect on reduction of HAuCl4 by trisodium citrate to form gold nanoplasmons (AuNPs) with a strong surface-enhanced Raman scattering (SERS) effect at 1615 cm-1 in the presence of molecular probe Victoria blue 4R (VB4r). SERS intensity increased with nanocatalyst GO concentration due to the formation of more AuNP substrates. The aptamer (Apt) of Hg2+ can bind to GO to form Apt-GO complexes, which can strongly inhibit nanocatalysis. When target Hg2+ is present, the formed stable Hg2+ -Apt complexes are separated from the GO surface, which leads to GO catalysis recovery. The enhanced SERS signal was linear to Hg2+ concentration in the range 0.25-10 nmol/L, with a detection limit of 0.08 nmol/L Hg2+ . Thus, a new gold nanoplasmon molecular spectral analysis platform was established for detecting Hg2+ , based on Apt regulation of GO nanocatalysis.


Assuntos
Aptâmeros de Nucleotídeos/química , Ouro/química , Grafite/química , Mercúrio/análise , Nanopartículas Metálicas/química , Óxidos/química , Catálise , Análise Espectral Raman , Propriedades de Superfície
19.
Mikrochim Acta ; 185(3): 177, 2018 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-29594714

RESUMO

The authors report that graphene oxide nanoribbons exert a strong catalytic effect on the reduction of HAuCl4 by H2O2 to form gold nanoparticles which display nanoplasmonic surface enhanced Raman scattering (SERS) activity, Rayleigh scattering and absorption. If an aptamer against Pb(II) is present in solution, it will bind to the graphene oxide nanoribbons and thereby inhibit their catalytic activity. Upon addition of Pb(II), it will bind to the aptamer to form stable complexes and release free graphene oxide nanoribbon. These cause the surface enhanced Raman scattering intensity at 1615 cm-1 to increase in the presence of the molecular probe Victoria Blue B. The SERS signal increases linearly in the 0.002-0.075 µmol·L-1 Pb(II) concentration range, and the detection limit is 0.7 nmol·L-1. Toner samples were spiked and then analyzed for Pb(II) by this method. Relative standard deviations are between 6.2% and 12.2%, and recoveries range from of 86.7%-106.7%. Graphic abstract Based on Pb(II) binds to the aptamer to form stable G-quadruplex and release free graphene oxide nanoribbon, a sensitive and selective surface enhanced Raman scattering method was developed for detection of 0.002-0.075 µmol·L-1 Pb(II) by using the molecular probe Victoria Blue B.

20.
Luminescence ; 31(3): 640-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26280554

RESUMO

Using AgNO3 as the precursor, stable silver nanochain (AgNC) sols, orange-red in color, were prepared using hydrazine hydrate. A strong surface plasmon resonance Rayleigh scattering (RRS) peak occurred at 420 nm plus two surface plasmon resonance (SPR) absorption peaks at 410 nm and 510 nm. Rhodamine S (RhS) cationic dye was absorbed on the as-prepared AgNC substrate to obtain a RhS-AgNC surface-enhanced Raman scattering (SERS) nanoprobe that exhibited a strong SERS peak at 1506 cm(-1) and a strong RRS peak at 375 nm. Upon addition of the analyte sodium hexametaphosphate (HP), it reacted with RhS, which resulted in a decrease in the SERS and RRS peaks that was studied in detail. The decreased SERS and RRS intensities correlated linearly with HP concentration in the range of 0.0125-0.3 µmol/L and 0.05-1.0 µmol/L, with a detection limit of 6 nmol/L and 20 nmol/L HP respectively. Due to advantages of high sensitivity, good selectivity and simple operation, the RhS molecular probes were used to determine HP concentration in real samples.


Assuntos
Corantes Fluorescentes/química , Nanopartículas Metálicas/química , Sondas Moleculares/química , Fosfatos/análise , Rodaminas/química , Prata/química , Ressonância de Plasmônio de Superfície
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