EUROPEAN POLYMER JOURNAL
·
2015
·
IF 3.005
Hongjing Ma,Aihua Li,Yuanhong Xu,Wenling Zhang,Jingquan Liu
Fabrication of metal-enhanced fluorescence (MEF) system with stimuli responsive “soft” shells is an efficient means to achieve tunable MEF behavior. In this article, pH responsive fluorophores modified polyacrylic acid (PAA) with tunable chain length was synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization using a rhodamine B (RB) functionalized RAFT agent, followed by the immobilization onto silver nanoparticles (AgNPs) via Ag–S coordination interaction to afford core–shell nanohybrids with AgNPs core, PAA shell and RB fluorophores on the surface. TEM and XPS analysis revealed that the polymer was successfully linked onto AgNPs surface. Our results revealed that the fluorescent intensity of AgNPs/polymer core–shell nanohybrids was sensitive extremely to the environmental pH values. All the maximal fluorescence intensities were observed at around pH 2, but slightly different. The maximal fluorescent intensity at pH 2 increased with the increasing polymer chain length first and then decreased. When the degree of polymerization (DP) of polymer was designed at 150, the maximal MEF was obtained. The size change of the core–shell nanohybrids with different environmental value was also supported by DLS analysis, which also manifested that the tunable MEF behavior was sensitive to the distance between the AgNPs and fluorophores. These pH responsive AgNPs/polymer core–shell nanohybrids may envision potential applications in drug delivery, sensors and nanodevices.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICS EXPRESS
·
2017
·Vol. 25
·期 9
·9901-9910
·
IF 3.307
Chao Chen,Ling Zhang,Min Yang,Chunxian Tao,Zhaoxia Han,Bin Chen,Heping Zeng
Nanoporous gold (NPG) has been reported to provide remarkable fluorescence enhancement of adjacent fluorophores due to the metal-enhanced fluorescence phenomenon (MEF), and the enhancement is related with the characteristic length of nanoporosity. To fully understand the effect of NPG on nearby fluorophores, it is desirable to study systems with well-defined metal-fluorophore distances. In this study we investigated the distance effect by using silica as the spacing layer between fluorophores and NPG. Originating from competition between plasmonic amplifying and metallic quenching, the dye molecule rhodamine 6G was best enhanced by 20-nm SiO2 coated nanoporous gold with the pore size of 36 nm, while the protein phycoerythrin was best enhanced by 15-nm SiO2 coated nanoporous gold with the pore size of 42 nm and the quantum dots were best enhanced by 20-nm SiO2 coated nanoporous gold with the pore size of 42 nm.
研究领域:
材料科学
·
光学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 54
·39908-39920
·
IF 3.9
Dabin Liu,Wenzhang Zhu,Bin Qiu,Shiqian Zhang
Research has shown that the expression level of microRNA-155 (miRNA-155) is positively correlated with clinical stage and depth of invasion in patients with cervical cancer and cervical intraepithelial neoplasia and tends to be highly expressed. Therefore, it is very important to develop sensitive miRNA-155 analysis methods for the early diagnosis, treatment, and prognostic evaluation of cervical cancer. In this study, a near-infrared light-driven fluorescent biosensor based on the metal-enhanced fluorescence effect of polydopamine-coated upconversion nanoparticle (UP/Au) and two toehold-mediated strand displacement (TMSD) steps was constructed for the detection of miRNA-155. The target miRNA-155 can undergo a TMSD1 reaction with single-stranded DNA1 (ssDNA1) modified on wrinkled silica (WSNs) to form the ssDNA1/miRNA-155 complex and expose toehold 2. Through the TMSD2 reaction, ssDNA2 adsorbed on the UP/Au surface reacts with ssDNA1 to form the ssDNA1/ssDNA2 complex, which replaces miRNA-155 and enables the recovery of the UP/Au fluorescence signal. The target miRNA-155 was reacted with the new ssDNA1 to amplify the detection signal, with a detection range of 0.5–20 pM and a detection limit of 19.76 fM for miRNA-155. In addition, the fluorescent biosensor has been applied for the analysis of miRNA-155 in serum samples, indicating its good practicality.
研究领域:
生物传感技术
·
分子诊断
·
癌症研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Yuan Wang,Lei Feng,Haiyan Zhu,Hongyan Miao,Ying Li,Xuefeng Liu,Gang Shi
The fluorescence intensity of the ring-opened merocyanine (MC) form of spiropyran can be enhanced by metal nanostructures. However, direct contact between spiropyran and the metal results in fluorescence quenching, which will reduce the enhancement amplitude of MC fluorescence. Here, Ag nanoparticles (NPs), a TiO2 dielectric layer, a poly(methyl methacrylate)-spiropyran (PMMA-SP) layer, and Au shell-isolated NPs with SiO2 shells (Au@SiO2) are successively assembled on a Si wafer with micropyramids and nanoholes (Siph). The hierarchical structure of this substrate is similar to insects’ compound eyes with nano- and microstructures, which can reduce the reflection of incident light. Meanwhile, the Au/Ag-coupled plasmonic nanocavities can enhance the intensity of a local electromagnetic (EM) field. In addition, TiO2 and SiO2 layers can avoid the nonradiative energy transfer caused by the direct contact between spiropyan and the metal. Based on the above advantages, the fluorescence enhancement factor (EF) of this substrate is as high as 195, which is the maximum reported so far. Zn2+, Cu2+, and Sn2+ can also be detected on Siph/TiO2/PMMA-SP/Au@SiO2, whose detection limits are 0.054, 0.038, and 0.049 μM, respectively. Furthermore, this substrate can be reused to detect metal ions by taking advantage of the reversible isomerization of spiropyran. The bioinspired substrate has positive significance in improving the fluorescence intensity of MC, and its lack of specific recognition ability for metal ions is expected to be further improved by molecular modification of spiropyran.
研究领域:
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
RARE METALS
·
2019
·Vol. 38
·期 12
·1178-1186
·
IF 1.785
Wang Jian-Chao,Luo Hong-Sheng,Zhang Ming-Hai,Zu Xi-Hong,Zhang Jie,Gu Yu-Xin,Yi Guo-Bin
A new substrate, aligned Ag nanowires decorated with silver nanoparticle composite structure (AgNWs@AgNPs), was fabricated to investigate metal-enhanced fluorescence (MEF) and its mechanism. The new composite structure was fabricated via a three-phase interface assembly method followed by SnCl 2 sensitization and AgNO 3 reduction process. The size and distribution of the nanoparticles on silver nanowires increased with the sensitization and reduction cycles. The formation of AgNPs on the surfaces of AgNWs was confirmed by multiple characterization methods including scanning electron microscopy (SEM), transmission electron microscope (TEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). The results show that the fluorescence intensity of the poly(3-hexylthiophene) (P3HT) on the composite structure was greatly enhanced compared with that on bare glass substrate, and the intensity increased with the increase in particle sizes and density. The mechanism was based on the increase in excitation rate and the radiation decay rate. The new type of substrate could serve as a good and efficient MEF substrate for high-performance fluorescence-based devices.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2014
·
IF 2.354
Bihua Xia,Xiaoyu Wang,Lidong Li
Hybrid thin biomacromolecular films were fabricated by combining the in situ formation of silver nanoparticles (Ag NPs) in gelatin and self-assembly of carboxymethyl chitosan (CCHI). The hybrid films exhibited excellent antibacterial activity toward Escherichia Coli . When the fluorescent dye 4,7-(9,9ʹ-bis(6-adenine hexyl)fluorenyl)-2,1,3-benzothiadiazole modified with nucleotide adenine and quaternary ammonium groups (OFBT-AA) was adsorbed onto the surface of the hybrid films, metal-enhanced fluorescence resulted in a maximum 5.3-fold increase in the fluorescence of OFBT-AA.
研究领域:
生物材料学
·
纳米生物学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-9
·
IF 3.159
Wei Xian,Mei Shiliang,Yang Dan,Zhang Guilin,Xie Fengxian,Zhang Wanlu,Guo Ruiqian
The tunable photoluminescence (PL) of nitrogen-doped carbon dots (NCDs) has attracted much attention in recent years while the specific mechanism is still in dispute. Herein, NCDs with yellow emission were successfully synthesized via a facile hydrothermal approach. Three kinds of post-treatment routes were investigated to verify the influence of surface states on the PL emission of NCDs including solvent-dependent, reduced-reaction and metal-enhanced effect. The interaction mechanism was studied by absorption spectrum, structural characterizations, steady-state and time-resolved spectroscopy. When dispersed in different solvents, the as-prepared NCDs show tunable emission and PL enhancement attributed to hydrogen bonding between solvents and NCDs. Besides, the addition of NaBH 4 can induce the reduction of the C=O bonds existing in original NCDs to C–O bonds and thus result in the enhancement of the intrinsic ( n – π *) emission. Moreover, metal-enhanced fluorescence of NCDs can also be observed when adding Ag + into initial NCD solution, which might be ascribed to aggregation-induced emission enhancement. These results for post-treated NCDs demonstrate that surface functional groups are responsible for PL emission and provide new possibilities like multi-image sensing and lighting application.
研究领域:
材料科学
·
光化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Sai Lin,Ziwei Wang,Yijun Zhang,Yunyun Huang,Rongrong Yuan,Weidong Xiang,Yongqiang Zhou
Ag nanoparticles (NPs) show a excellent surface plasmon resonance (SPR), which is expected to enable fluorescence enhancement. In this study, a facile approach is proposed for fabrication of Ag NPs/long-wavelength carbon dots (Ag-LCDs) hybrids, wherein Ag NPs work as a fluorescent reinforcer to enhance photoluminescence (PL) intensity of LCDs. The largest enhancement was acquired through adjusting the volume ration between Ag NPs and LCDs. In this process, PL decay is considered as an important and simple characterization to speculate the metal enhanced fluorescence (MEF) mechanism. On the basis of result of small reduction in lifetime, we proposed that the mechanism may be predominantly derived from the localized effectric field effect and partly from the intrinsic radiative decay rate. Moreover, spin-coating technology was utilized to produce LCDs and Ag-LCDs hybrids films. Then, white light-emitting diodes (white LEDs) were constructed by these films with controllable thicknesses and GaN chips. The constructed white LED presented excellent optical performances with an optimal color coordinates (CIE) of (0.33, 0.35), a color rendering index (CRI) of 74.6, a correlated color temperature (CCT) of 5435 K. Notably, the existence of Ag NPs enable these LCDs to improve the luminous efficacy (LE) from 32.63 lm W −1 to 41.26 lm W −1 . Such superior optical merits enable them the promising potentials for application in optical devices.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2019
·
IF 4.916
Wei He,Xiangying Sun,Bin Liu,Jiangshan Shen
In this paper, deoxyribonucleic acid (DNA) with different lengths were used to control the distance between carbon dots (CDs) and silver nanoparticles (AgNPs) in self-assembled multilayers (SAMs). Surface-enhanced fluorescence and fluorescence resonance energy transfer (SEF-FRET) could be achieved based on changing DNA strands. The fluorescence intensity of CDs SAMs with 6-base DNA strands could be enhanced up to ca. 5.6 times by AgNPs. As-fabricated CDs SAMs with excellent luminescent properties, superior stability have been employed for the development of a label-free fluorescence sensing platform for DNA detection. Since DNA would hybridize with the complemented one which was attached on the surface of SAMs, resulting in a close distance between CDs and AgNPs, FRET could thus occur between AgNPs and CDs, resulting in quenching the fluorescence of CDs SAMs. This sensitive sensing platform could show excellent analytical performance for detecting DNA with a linear response ranging from 93.07 pM to 5.433 nM and a detection limit of 16.36 pM, which could be further employed to probe human blood samples. This could prove a promising method for the detection of DNA.
研究领域:
生物化学
·
纳米技术
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Sixiang Zhao,Yingying Yu,Boyu Zhang,Pu Feng,Congcong Dang,Ming Li,Liancheng Zhao,Liming Gao
Circularly polarized (CP) light has attracted wide attention for its great potential in broad applications. However, it remains a challenge to generate left-handed and right-handed circularly polarized (LCP and RCP) light from cellulose nanocrystal (CNC)-based materials only with an intrinsic left-handed chiral structure, owing to the pattern of CP light emission primarily based on the chirality of materials. Herein, a separation structure of luminophore layers and chiral CNCs was provided to achieve dual-mode CP light emission by building a luminophore–chiral CNC interface. By directly exciting the back and front of two-layer films, LCP and RCP light could be easily emitted without any assisting means and specific setting angles. In addition, owing to the formation of the luminophore–chiral CNC interface, metal-enhanced fluorescence (MEF) was achieved to offset the brightness loss caused by circular polarization. By incorporating gold triangular nanoprisms in CNC chiral layers, the fluorescence enhancement of the ensemble was as high as 6.5-fold. The decisive role of the luminophore–chiral CNC interface in enhancing luminescence and dual-mode CP light emission was carefully investigated by contrasting the systems with and without luminophore–chiral CNC interfaces in this study. We believe that this dual-mode CP light emission film with MEF enables a promising approach to extending the application of CP light materials.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
Nanoscale
·
2014
·Vol. 6
·期 15
·8681-8693
·
IF 6.739
Xuefan Gu,Youshen Wu,Lingze Zhang,Yongchun Liu,Yan Li,Yongli Yan,Daocheng Wu
To improve the metal-enhanced fluorescence (MEF) effect of nanogolds (AuNPs) and accurately detect specific DNA sequences via DNA hybridization, novel hybrid magnetic nanoparticles/nanogold clusters (HMNCs) were designed based on finite-difference time-domain simulation results and prepared by using Fe3O4 and nanogolds. The nanogolds outside the HMNC were then conjugated with thiol-terminated DNA molecules, thus DNA modified-HMNCs (DNA–HMNCs) were obtained. The size distributions of these nanostructures were measured by a Malvern size analyzer, and their morphology was observed via transmission electron microscopy (TEM). The ultraviolet (UV)-visible (vis) absorption spectra of the samples were recorded with a UV-2600 spectrophotometer. Fluorescence spectra and the MEF effect were recorded using a spectrophotofluorometer, and lifetimes were determined using a time-correlated single photon counting apparatus. The prepared HMNCs were stable in aqueous solutions and had an average diameter of 87 ± 3.2 nm, with six to eight AuNPs around a single Fe3O4 nanoparticle. Fluorescein isothiocyanate (FITC) tagged DNA–HMNC conjugates exhibited a significant MEF effect and could accurately detect specific DNA sequences after DNA hybridization. This result indicates their various potential applications in sensors and biomedical fields.
研究领域:
生物化学
·
纳米医学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Ran Gao,Xueqin Li,Rongxiu Zhu,Xia Wu
We found an exciting fluorescence enhancement phenomenon of ferulic acid (FA) and magnesium ions in strong alkaline medium. In KCl/NaOH buffer solution with pH = 12.30, Mg 2+ ions could coordinate with FA to generate Mg-FA complex ions and also combined with hydroxide ions to form Mg(OH) 2 nanosheets, and then the nanosheets further aggregated into Mg(OH) 2 -micro/nanoparticles (Mg(OH) 2 -MNPs). The Mg(OH) 2 -MNPs acted as potential matrix materials for surface-enhanced fluorescence (SEF). In this work, the fluorescence quantum yield and the fluorescence intensity of FA were significantly increased by about 50 times and hundreds of times by freshly formed Mg(OH) 2 -MNPs, respectively. Then, a highly sensitive method was developed for quantitative detection of FA. The fluorescence intensity at 440 nm under 370 nm light irradiation showed a good linearity with FA concentration in the range of 9.0 × 10 −10 to 1.0 × 10 –6 M ( R 2 = 0.9984), and the limit of detection (at S/N = 3) was 2.7 × 10 −10 M. And then a convenient method for FA detection by smartphone assisted was also proposed. These methods were applied for detecting FA in real samples, and the recovery rates were range from 98.3 % to 103.1 %. This work provided an effective way for improving FA analytical sensitivity.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）