Chinese Physics B
·
2022
·Vol. 31
·期 3
·037803
·
IF 1.652
Hongwen Cao,Liting Guo,Zhen Sun,Tifeng Jiao,Mingli Wang
Wheat leaves with natural microstructures as substrates were covered by the silver nanoislands by magnetron to prepare a low-cost, environment-friendly and mass production surface-enhanced fluorescence (SEF) substrate (Ag-WL substrate). The best SEF substrate was selected by repeatly certifying the fluorescence intensity of 10−5 M Rhodamine B (RB) and 10−5 M Rhodamine 6G (R6G) aqueous solutions. The abundant semi-spherical protrusions and flake-like structures on the surface of the Ag-WL substrate produce high-density hot spots, which provides a new and simple idea for the preparation of biomimetic materials. The results of 3D finite-different time-domain (FDTD) simulation show that the nanoisland gap of semi-spherical protrusions and flake-like structures has produced rich hotspots. By adjusting the time of magnetron sputtering, the enhancement factor (EF) was as high as 839 times, relative standard deviation (RSD) reached as low as 10.7%, and the substrate was very stable and repeatable, which shows that Ag-WL substrate is trustworthy. Moreover, semi-spherical protrusions provide stronger surface-enhanced Raman scattering (SERS) effects compared to flake-like structure. What is more surprising is that the detection limit of the substrate for toxic substance crystal violet (CV) is as low as 10−10 M.
研究领域:
材料科学
·
生物仿生学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2022
·
IF 6.556
XueQin Li,Xingcen Liu,Yujie Liu,Ran Gao,Xia Wu,Xibao Gao
We developed a trace level detection method for dopamine (DA) based on the metal-enhanced fluorescence (MEF) effect of gold nanoflowers (AuNFs). AuNFs prepared were excellent enhancement fluorescence substrates due to their unique morphology with rich edges and sharp quoins. DA was the target analyte and also as a bridge reagent that could regulate the distance between AuNFs and Tb 3+ . The characteristic fluorescence of Tb 3+ was enhanced significantly through the synergistic effect between the luminescence sensitized by DA and the MEF caused by AuNFs. Under the optimum experimental conditions, the fluorescence intensity of Tb 3+ at 545 nm demonstrated very significant sensing ability against DA concentration and showed a good linear relationship in the range of 0.80–300 nM and the limit of detection was 0.21 nM ( S/N = 3). The proposed method was also validated in serum samples and the dopamine hydrochloride injection samples with satisfactory results.
研究领域:
分析化学
·
生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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
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纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 2
·1-8
·
IF 6.232
Yang Weiqiang,Zhang Guiyun,Ni Jiancong,Lin Zhenyu
Fluorescent nanoparticles were prepared by encapsulating carbon dots (CDs) within silica spheres and then modifying these spheres with amino groups (CD@SiO 2 -NH 2 ). On the basis of the silver mirror reaction, Ag + assembled on the surface of CD@SiO 2 -NH 2 is reduced to silver nanoparticles (AgNPs) by formaldehyde. The in-situ grown AgNPs cause a visually distinguishable fluorescence enhancement. This metal-enhanced effect was investigated by transmission electron microscopy and spectroscopic characterization, and the relevant conditions were optimized. CD@SiO 2 -NH 2 -Ag + fluorescent probes were loaded onto nano-sponge pieces for the analysis of formaldehyde gas. The blue fluorescence emission (peaking at 466 nm) in response to formaldehyde is greatly enhanced (up to 5.2 times) over other species. There is a linear relationship between the fluorescence enhancement and formaldehyde gas concentration in the range of 10 ppb to 1 ppm, and the detection limit is 3 ppb. The fluorimetric assay needs 30 min for the reaction, and the fluorescent nano-sponge pieces are disposable.
Schematic representation of the metal-enhanced fluorescence (MEF) induced by in-situ grown silver nanoparticles on silica-encapsulated carbon dots, and its application in formaldehyde gas assays.
研究领域:
分析化学
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
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
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Weidao Yu,Wen Sun,Ketong Guo,Yaqiong Yang
Lipopolysaccharide (LPS) as the component of cell membrane on gram-negative bacteria played a central role on inflammatory inducer to stimulate a multi-system host response. Herein, a surface-enhanced fluorescent (SEF) sensor was developed for LPS analysis based on shell-isolated nanoparticles (SHINs). The fluorescent signal of CdTe quantum dots (QDs) was amplified by silica shell-coated Au nanoparticles (Au NPs). The 3D finite-difference time-domain (3D-FDTD) simulation revealed that this enhancement was due to local electric field amplification. This method has a linear detection range of 0.1–20 μg/mL and a detection limit of 64 ng/mL for LPS. Furthermore, the developed method was successfully applied for LPS analysis in milk and human serum sample. The results indicated that the as-prepared sensor has significant potential for selective detection of LPS in biomedical diagnosis and food safety.
研究领域:
生物医学
·
食品安全
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
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
危险品化学品经营许可证（带存储）