Green Synthesis of Fluorescent Ag Nanoclusters for Detecting Cu2+ Ions and Its “Switch-On” Sensing Application for GSH

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.

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A Turn-On Detection of DNA Sequences by Means of Fluorescence of DNA-Templated Silver Nanoclusters via Unique Interactions of a Hydrated Ionic Liquid

Molecules ◽

10.3390/molecules23112889 ◽

2018 ◽

Vol 23 (11) ◽

pp. 2889 ◽

Cited By ~ 6

Author(s):

Ye Teng ◽

Hisae Tateishi-Karimata ◽

Takaaki Tsuruoka ◽

Naoki Sugimoto

Keyword(s):

Ionic Liquid ◽

Dna Sequences ◽

Fluorescence Emission ◽

Silver Nanoclusters ◽

Dihydrogen Phosphate ◽

Target Sequence ◽

Aqueous Buffer ◽

Turn On ◽

Sensitivity And Selectivity ◽

Ag Ncs

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.

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Silk fibroin-derived peptide directed silver nanoclusters for cell imaging

RSC Advances ◽

10.1039/c8ra04607g ◽

2018 ◽

Vol 8 (49) ◽

pp. 27805-27810 ◽

Cited By ~ 4

Author(s):

Peng Gao ◽

Hao Wang ◽

Guifu Zou ◽

Ke-Qin Zhang

Keyword(s):

Silk Fibroin ◽

Heavy Chain ◽

Cell Imaging ◽

Synthesis Method ◽

Green Light ◽

Silver Nanoclusters ◽

Facile Synthesis ◽

One Pot ◽

Ag Ncs

Fluorescent silver nanoclusters (Ag NCs) that are capable of emitting green light have been synthesized using a peptide derived from the C terminal of silk fibroin heavy chain (CSH) via a one-pot, green, and facile synthesis method.

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Amplified Fluorescent Aptasensor for Ochratoxin A Assay Based on Graphene Oxide and RecJf Exonuclease

Toxins ◽

10.3390/toxins12110670 ◽

2020 ◽

Vol 12 (11) ◽

pp. 670

Author(s):

Han Zhao ◽

Dehui Xiong ◽

Ying Yan ◽

Changbei Ma

Keyword(s):

Graphene Oxide ◽

Ochratoxin A ◽

Signal Amplification ◽

Red Wine ◽

Limit Of Detection ◽

Experimental Conditions ◽

Fluorescent Sensing ◽

Sensing System ◽

Sensing Platform ◽

Fluorescent Response

In this study, we developed an aptamer-based fluorescent sensing platform for the detection of ochratoxin A (OTA) based on RecJf exonuclease-assisted signal amplification and interaction between graphene oxide (GO) and the OTA aptamer (OTA-apt). After optimizing the experimental conditions, the present aptamer-based sensing system can exhibit excellent fluorescent response in the OTA assay, with a limit of detection of 0.07 ng/mL. In addition to signal amplification, this strategy is also highly specific for other interfering toxins. Furthermore, this aptasensor can be reliably used for assessing red wine samples spiked with different OTA concentrations (2.4, 6 and 20 ng/mL). The proposed assay plays an important role in the field of food safety and can be transformed for detecting other toxins by replacing the sequence that recognizes the aptamer.

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A Compact Detection Platform Based on Gradient Guided-Mode Resonance for Colorimetric and Fluorescence Liquid Assay Detection

Sensors ◽

10.3390/s21082797 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2797

Author(s):

Jing-Jhong Gao ◽

Ching-Wei Chiu ◽

Kuo-Hsing Wen ◽

Cheng-Sheng Huang

Keyword(s):

Limit Of Detection ◽

Detection System ◽

Fluorescence Emission ◽

Assay Sensitivity ◽

Detection Range ◽

Current Form ◽

Guided Mode ◽

Spectral Detection ◽

Guided Mode Resonance ◽

Colorimetric Assays

This paper presents a compact spectral detection system for common fluorescent and colorimetric assays. This system includes a gradient grating period guided-mode resonance (GGP-GMR) filter and charge-coupled device. In its current form, the GGP-GMR filter, which has a size of less than 2.5 mm, can achieve a spectral detection range of 500–700 nm. Through the direct measurement of the fluorescence emission, the proposed system was demonstrated to detect both the peak wavelength and its corresponding intensity. One fluorescent assay (albumin) and two colorimetric assays (albumin and creatinine) were performed to demonstrate the practical application of the proposed system for quantifying common liquid assays. The results of our system exhibited suitable agreement with those of a commercial spectrometer in terms of the assay sensitivity and limit of detection (LOD). With the proposed system, the fluorescent albumin, colorimetric albumin, and colorimetric creatinine assays achieved LODs of 40.99 and 398 and 25.49 mg/L, respectively. For a wide selection of biomolecules in point-of-care applications, the spectral detection range achieved by the GGP-GMR filter can be further extended and the simple and compact optical path configuration can be integrated with a lab-on-a-chip system.

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Fluorescent sensing of ascorbic acid based on iodine induced oxidative etching and aggregation of lysozyme-templated silver nanoclusters

Analytica Chimica Acta ◽

10.1016/j.aca.2017.11.068 ◽

2018 ◽

Vol 1003 ◽

pp. 49-55 ◽

Cited By ~ 17

Author(s):

Qinchao Mo ◽

Fang Liu ◽

Jing Gao ◽

Meiping Zhao ◽

Na Shao

Keyword(s):

Ascorbic Acid ◽

Silver Nanoclusters ◽

Fluorescent Sensing ◽

Oxidative Etching

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A Novel Photosynthesis of Carboxymethyl Starch-Stabilized Silver Nanoparticles

The Scientific World JOURNAL ◽

10.1155/2014/514563 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 8

Author(s):

M. A. El-Sheikh

Keyword(s):

Silver Nanoparticles ◽

Room Temperature ◽

Colloidal Solution ◽

Synthesis Method ◽

Silver Ions ◽

Water Soluble ◽

Synthesis Process ◽

Carboxymethyl Starch ◽

Round Shape ◽

First Time

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40°C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25°C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1–21 nm and the highest counts % of these particles were for particles of 6–10 and 1–3 nm, respectively.

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Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.281.40 ◽

2018 ◽

Vol 281 ◽

pp. 40-45

Author(s):

Jie Guang Song ◽

Lin Chen ◽

Cai Liang Pang ◽

Jia Zhang ◽

Xian Zhong Wang ◽

...

Keyword(s):

Particle Size ◽

Calcination Temperature ◽

Hydrothermal Reaction ◽

Synthesis Method ◽

Particle Morphology ◽

Precipitation Method ◽

Molar Ratio ◽

Synthesis Process ◽

Powder Materials ◽

Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

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Label-free DNA detection based on oligonucleotide-stabilized silver nanoclusters and exonuclease III-catalyzed target recycling amplification

Analytical Methods ◽

10.1039/c4ay00838c ◽

2014 ◽

Vol 6 (15) ◽

pp. 6082-6087 ◽

Cited By ~ 6

Author(s):

Hui Ma ◽

Wei Wei ◽

Qian Lu ◽

Zhixin Zhou ◽

Henan Li ◽

...

Keyword(s):

High Sensitivity ◽

Silver Nanoclusters ◽

Label Free ◽

Exonuclease Iii ◽

Target Recycling ◽

Free Dna ◽

Sensitivity And Selectivity ◽

Exo Iii ◽

Ag Ncs ◽

Recycling Amplification

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

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