Target-Activating and Toehold Displacement Ag NCs/GO Biosensor-Mediating Signal Shift and Enhancement for Simultaneous Multiple Detection

Author(s):  
Da-Qian Feng ◽  
Guoliang Liu
Keyword(s):  
2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Nur Aimi Jani ◽  
Choonyian Haw ◽  
Weesiong Chiu ◽  
Saadah Abdul Rahman ◽  
Poisim Khiew ◽  
...  

Current work reports the study of Ag nanocrystals (NCs) decorated doubly anodized (DA) TiO2 nanotubes (NTs) thin film as an efficient photoelectrode material for water splitting and photocatalytic hydrogen gas production. DA process has been shown to be capable of producing less defective NTs and creating additional spacious gaps in between NT bundles to allow efficient and uniform integration of Ag NCs. By employing photoreduction method, Ag NCs can be deposited directly onto NTs, where the size and density of coverage can be maneuvered by merely varying the concentration of Ag precursors. Field emission scanning electron microscope (FESEM) images show that the Ag NCs with controllable size are homogeneously decorated onto the walls of NTs with random yet uniform distribution. X-ray diffraction (XRD) results confirm the formation of anatase TiO2 NTs and Ag NCs, which can be well indexed to standard patterns. The decoration of metallic Ag NCs onto the surface of NTs demonstrates a significant enhancement in the photoconversion efficiency as compared to that of pristine TiO2 NTs. Additionally, the as-prepared nanocomposite film also shows improved efficiency when used as a photocatalyst platform in the production of hydrogen gas. Such improvement in the performance of water splitting and photocatalytic hydrogen gas production activity can be credited to the surface plasmonic resonance of Ag NCs present on the surface of the NTs, which renders improved light absorption and better charge separation. The current work can serve as a model of study for designing more advanced nanoarchitecture photoelectrode for renewable energy application.


2015 ◽  
Vol 51 (6) ◽  
pp. 1100-1103 ◽  
Author(s):  
Etery Sharon ◽  
Natalie Enkin ◽  
H. Bauke Albada ◽  
Itamar Willner

A supramolecular DNA nanocluster consisting of Ag NCs allows the luminescence detection and multiplexed analysis of ligand–aptamer complexes.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2889 ◽  
Author(s):  
Ye Teng ◽  
Hisae Tateishi-Karimata ◽  
Takaaki Tsuruoka ◽  
Naoki Sugimoto

Nucleic acid stability and structure, which are crucial to the properties of fluorescent DNA-templated silver nanoclusters (DNA-Ag NCs), significantly change in ionic liquids. In this work, our purpose was to study DNA-Ag NCs in a buffer containing the hydrated ionic liquid of choline dihydrogen phosphate (choline dhp) to improve fluorescence for application in DNA detection. Due to the stabilisation of an i-motif structure by the choline cation, a unique fluorescence emission—that was not seen in an aqueous buffer—was observed in choline dhp and remained stable for more than 30 days. A DNA-Ag NCs probe was designed to have greater fluorescence intensity in choline dhp in the presence of a target DNA. A turn-on sensing platform in choline dhp was built for the detection of the BRCA1 gene, which is related to familial breast and ovarian cancers. This platform showed better sensitivity and selectivity in distinguishing a target sequence from a mutant sequence in choline dhp than in the aqueous buffer. Our study provides new evidence regarding the effects of structure on properties of fluorescent DNA-Ag NCs and expands the applications of fluorescent DNA-Ag NCs in an ionic liquid because of improved sensitivity and selectivity.


2014 ◽  
Vol 6 (15) ◽  
pp. 6082-6087 ◽  
Author(s):  
Hui Ma ◽  
Wei Wei ◽  
Qian Lu ◽  
Zhixin Zhou ◽  
Henan Li ◽  
...  

A label-free DNA biosensor with high sensitivity and selectivity is constructed by using DNA–Ag NCs and Exo III-catalyzed target recycling amplification.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Feng Shan ◽  
Tong Zhang ◽  
Sheng-Qing Zhu

The effects of corner shape of silver (Ag) nanocubes (NCs) on optical absorptions of organic solar cells (OSCs) are theoretically investigated by finite element method (FEM) calculations. The absorption of sun light in the active layer is calculated. Significant absorption enhancements have been demonstrated in metallic region with different shapes of Ag NCs, among them corner radius (R) is zero result in the best light absorption performance of up to 55% enhancement with respect to bare OSCs. The origins of increased absorption are believed to be the effects of the huge electric field enhancement and increased scattering upon the excitation of localized surface plasmon resonance (LSPR). Apart from usingR=0, we show thatR=3, 6, and 11.29 of Ag NCs in metallic region of active layer may also result in the maximum comparable absorption enhancement of 49%, 41%, and 28%, respectively. In addition, a significant effect of the period of NCs is observed.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yunpeng Shang ◽  
Hui Gao ◽  
Lei Li ◽  
Chaoqun Ma ◽  
Jiao Gu ◽  
...  

Herein, we prepared the L-histidine- (His-) protected silver nanoclusters (Ag NCs) by the microwave synthesis method. The synthesis process was rapid, facile, and environmentally friendly. Under 356 nm excitation, the as-prepared Ag NCs exhibited the blue fluorescence, and the fluorescence emission peak was located at 440 nm. The Ag NCs could successfully detect trace copper (Cu2+) ions in the aqueous solution and the limit of detection (LOD) was as low as 0.6 pM. Interestingly, the Ag NCs showed a different pH-dependent selectivity for both Cu2+ and iron (Fe3+) ions with no responses to other heavy metal ions. Furthermore, the as-fabricated fluorescent sensing system was utilized to detect glutathione (GSH, the LOD was 0.8 nM) by using the “switch-on” fluorescence recovery of Ag NCs through adding glutathione (GSH) to the Cu2+-Ag NCs solution.


Author(s):  
E. Gazzola ◽  
A. Pozzato ◽  
G. Ruffato ◽  
E. Sovernigo ◽  
A. Sonato

AbstractSurface plasmon resonance biosensors have recently known a rapid diffusion in the biological field and a large variety of sensor configurations is currently available. Biological applications are increasingly demanding sensor miniaturization, multiple detection in parallel, temperature-controlled environment and high sensitivity. Indeed, versatile and tunable sensing platforms, together with an accurate biological environment monitoring, could improve the realization of custom biosensing devices applicable to different biological reactions. Here we propose a smart and high throughput fabrication protocol for the realization of a custommicrofluidic plasmonic biochip that could be easily tuned and modified to address different biological applications. The sensor chip here presented shows a high sensing capability, monitored by an accurate signal calibration in the presence of concentration and temperature variation.


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