scholarly journals Black phosphorus-Au nanocomposite-based fluorescence immunochromatographic sensor for high-sensitive detection of zearalenone in cereals

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2397-2406
Author(s):  
Shijie Li ◽  
Fuyuan Zhang ◽  
Junping Wang ◽  
Wenjun Wen ◽  
Shuo Wang
Keyword(s):  
Quantum Dots ◽  
Food Safety ◽  
Fluorescence Quenching ◽  
Density Functional ◽  
Limit Of Detection ◽  
Black Phosphorus ◽  
Sensitive Detection ◽  
The Density Functional Theory ◽  
Quenching Efficiency ◽  
Novel Method

AbstractRapid and high-sensitive detection of mycotoxins is believed to be of vital importance in assuring food safety. In this study, we developed a novel fluorescence immunochromatographic sensor (ICS) for the mycotoxin of zearalenone (ZEN) in cereals. This was done by using a black phosphorus-Au nanocomposite (BP-Au) as the 2D quenching platform. Herein, gold nanoparticles (AuNPs) were directly reduced on the surface of BP nanosheets (BPNSs) to form BP-Au nanocomposites, showing higher fluorescence (quantum dots, λEm = 525 nm) quenching efficiency compared to the BPNSs and AuNPs. The fluorescence quenching efficiency of the prepared BP-Au nanocomposite reached 73.8%, which was 1.73-fold and 1.44-fold higher than AuNPs and BPNSs, respectively. The density functional theory was also successfully used to explore the formation mechanism of the BP-Au nanocomposite. By introducing the quantum dots/BP-Au signal/quencher pair, a high-sensitive fluorescence quenching ICS (B-FICS) was developed for the detection and discrimination of ZEN with the limit of detection of 0.1 μg/l in pure working buffer. This was 2.5-fold more sensitive than AuNPs-based FICS (A-FICS). The B-FICS was successfully applied in real cereals detection with the sample limit of detection of 2 μg/kg. The successful construction of B-FICS offers a novel method for a rapid and high-sensitive detection of ZEN in cereals. It also provides a new practical application of 2D BPNSs in food safety sensing.

scholarly journals Molecularly Imprinted Silica-Coated CdTe Quantum Dots for Fluorometric Determination of Trace Chloramphenicol

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5965
Author(s):  
Xiaoxiao Chen ◽  
Yang Liu ◽  
Pu Li ◽  
Yichen Xing ◽  
Chaobiao Huang
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Recognition System ◽  
Electron Transfer Reaction ◽  
Trace Detection ◽  
Molecularly Imprinted ◽  
Specific Recognition ◽  
Quenching Efficiency ◽  
Photo Induced Electron Transfer

A dual recognition system with a fluorescence quenching of quantum dots (QDs) and specific recognition of molecularly imprinted polymer (MIP) for the detection of chloramphenicol (CAP) was constructed. MIP@SiO2@QDs was prepared by reverse microemulsion method with 3-aminopropyltriethoxysilane (APTS), tetraethyl orthosilicate (TEOS) and QDs being used as the functional monomer, cross-linker and signal sources, respectively. MIP can specifically recognize CAP, and the fluorescence of QDs can be quenched by CAP due to the photo-induced electron transfer reaction between CAP and QDs. Thus, a method for the trace detection of CAP based on MIP@SiO2@QDs fluorescence quenching was established. The fluorescence quenching efficiency of MIP@SiO2@QDs displayed a desirable linear response to the concentration of CAP in the range of 1.00~4.00 × 102 μmol × L−1, and the limit of detection was 0.35 μmol × L−1 (3σ, n = 9). Importantly, MIP@SiO2@QDs presented good detection selectivity owing to specific recognition for CAP, and was successfully applied to quantify CAP in lake water with the recovery ranging 102.0~104.0%, suggesting this method has the promising potential for the on-site detection of CAP in environmental waters.

scholarly journals One-Step Preparation of Nitrogen-Doped Graphene Quantum Dots With Anodic Electrochemiluminescence for Sensitive Detection of Hydrogen Peroxide and Glucose

2021 ◽  
Vol 9 ◽  
Author(s):  
Zheng Yanyan ◽  
Jing Lin ◽  
Liuhong Xie ◽  
Hongliang Tang ◽  
Kailong Wang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Quantum Dots ◽  
Limit Of Detection ◽  
Hydrothermal Process ◽  
Graphene Quantum Dots ◽  
Sensitive Detection ◽  
Uniform Size ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
One Step

Simple and efficient synthesis of graphene quantum dots (GQDs) with anodic electrochemiluminescence (ECL) remains a great challenge. Herein, we present an anodic ECL-sensing platform based on nitrogen-doped GQDs (N-GQDs), which enables sensitive detection of hydrogen peroxide (H2O2) and glucose. N-GQDs are easily prepared using one-step molecular fusion between carbon precursor and a dopant in an alkaline hydrothermal process. The synthesis is simple, green, and has high production yield. The as-prepared N-GQDs exhibit a single graphene-layered structure, uniform size, and good crystalline. In the presence of H2O2, N-GQDs possess high anodic ECL activity owing to the functional hydrazide groups. With N-GQDs being ECL probes, sensitive detection of H2O2 in the range of 0.3–100.0 μM with a limit of detection or LOD of 63 nM is achieved. As the oxidation of glucose catalyzed by glucose oxidase (GOx) produces H2O2, sensitive detection of glucose is also realized in the range of 0.7–90.0 μM (LOD of 96 nM).

scholarly journals Label-Free Sensitive Detection of Steroid Hormone Cortisol Based on Target-Induced Fluorescence Quenching of Quantum Dots

Langmuir ◽  
2020 ◽  
Vol 36 (27) ◽  
pp. 7781-7788
Author(s):  
Ye Liu ◽  
Bo Wu ◽  
Ekembu K. Tanyi ◽  
Sanjida Yeasmin ◽  
Li-Jing Cheng
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Steroid Hormone ◽  
Sensitive Detection ◽  
Label Free

scholarly journals Size engineering optoelectronic features of C, Si and CSi hybrid diamond-shaped quantum dots

RSC Advances ◽  
2019 ◽  
Vol 9 (49) ◽  
pp. 28609-28617 ◽  
Author(s):  
H. Ouarrad ◽  
F.-Z. Ramadan ◽  
L. B. Drissi
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Ab Initio ◽  
Density Functional ◽  
Optoelectronic Properties ◽  
Many Body ◽  
Functional Theory ◽  
The Density Functional Theory

Based on the density functional theory and many-body ab initio calculations, we investigate the optoelectronic properties of diamond-shaped quantum dots based graphene, silicene and graphene–silicene hybrid.

Highly sensitive detection of 2,4,6-trinitrophenol (TNP) based on lysozyme capped CdS quantum dots

RSC Advances ◽  
2015 ◽  
Vol 5 (63) ◽  
pp. 51428-51434 ◽  
Author(s):  
Weidan Na ◽  
Xiaotong Liu ◽  
Shu Pang ◽  
Xingguang Su
Keyword(s):  
Quantum Dots ◽  
Sensitive Detection ◽  
Nitroaromatic Compound ◽  
Cds Quantum Dots ◽  
Highly Sensitive ◽  
Novel Method ◽  
Cds Qds ◽  
Highly Sensitive Detection

This work presents a novel method for nitroaromatic compound detection using lysozyme-capped CdS quantum dots (Lys-CdS QDs).

Enhancement of the Fluorescence Quenching Efficiency of DPPH• on Colloidal Nanocrystalline Quantum Dots in Aqueous Micelles

2011 ◽  
Vol 21 (5) ◽  
pp. 1941-1949 ◽  
Author(s):  
Tuanjai Noipa ◽  
Surangkhana Martwiset ◽  
Nutthaya Butwong ◽  
Thawatchai Tuntulani ◽  
Wittaya Ngeontae
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Quenching Efficiency ◽  
Aqueous Micelles

Fabrication of a Dopamine Sensor Based on Carboxyl Quantum Dots

2015 ◽  
Vol 15 (10) ◽  
pp. 7871-7875 ◽  
Author(s):  
Fei Zhao ◽  
Jongsung Kim
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Fluorescence Quenching ◽  
Fluorescence Intensity ◽  
Limit Of Detection ◽  
Simple Procedure ◽  
Electronic Energy ◽  
Solution Ph ◽  
Electronic Energy Transfer

A quantum dot (QD)-based optical biosensor was developed to detect the activity of dopamine (DA) via the quenching of QD fluorescence intensity. In this study, we examined the fluorescence quenching of DA-conjugated quantum dots (DA@QDs) at various solution pH values. The fluorescence intensity of the QDs is quenched by electronic energy transfer from the QDs to the o-quinone group of dopamine oxide. The degree of fluorescence quenching was dependent on DA concentration. The influence of the external environment pH factor on fluorescence quenching was investigated. The results showed that the degree of fluorescence quenching of DA@QDs was highest in a slightly alkaline solution-pH of approximately 9. Fluorescence enhancement with increased pH appears to be due to electronic energy transfer, which is related to an increased degree of dopamine-o-quinone oxidation. The fluorescence quenching of QDs by DA is of considerable interest due to its potential for the direct detection of the DA in vivo via a simple procedure with a very low limit of detection.

scholarly journals A novel method for the synthesis of MOF-199 for Sensing and Photocatalytic Applications

2021 ◽  
Author(s):  
Deepika Garg ◽  
Heena Rekhi ◽  
Harpreet Kaur ◽  
Karam Jeet Singh ◽  
Ashok Kumar Malik
Keyword(s):  
Density Functional ◽  
Limit Of Detection ◽  
Average Length ◽  
Aqueous Media ◽  
Spectroscopic Studies ◽  
Blue Dye ◽  
Face Centered Cubic ◽  
Quenching Rate ◽  
X Ray ◽  
Quenching Efficiency

Abstract Multifunctional Cu (II)-based Metal Organic Framework (MOF) [Cu3(BTC)2] has been synthesized by a facile electrochemical method. Crystallographic and morphological characterizations of synthesized MOF have been done using Powder X-ray Diffractometer and Scanning Electron Microscope (SEM), respectively, whereas Fourier Transform Infrared Spectroscopy (FT-IR), Energy Dispersive X-ray Spectroscopy (EDS), UV-Vis Absorption Spectroscopy and Energy Resolved Luminescence Spectroscopic studies have been used for the detailed qualitative, quantitative as well as optical analyses. Sharp PXRD peaks indicate the formation of highly crystalline MOF with face centered cubic (fcc) structure. Flakes (average length = 0.71µm and width = 0.10 µm) and rods (average aspect ratio = ((0.1:8.3) µm) like morphologies have been observed in SEM micrographs. The presence of C, O and Cu has been confirmed by EDS analysis. Photocatalytic activity potential of the synthesized MOF has been tested using methylene blue dye (MB) as a test contaminant in aqueous media under sunlight irradiation. Selective and sensitive fluorescent sensing of different Nitroaromatic compounds (NACs) like 4-Nitroaniline (4-NA), 2-Nitroaniline (2-NA), 3-Nitroaniline (3-NA), 4-Nitrotoulene (4-NT), 2,4-Dinitrotoulene (2,4-DNT), 1,3-Dinitrobenzene (1,3-DNB), 2,6-Dinitrotoulene (2,6-DNT) has been done by exploring the photoluminescent behaviour of chemically stable Cu3(BTC)2. Synthesized MOF is extremely sensitive towards 4-NA, which is having PL quenching efficiency of 82.61% with highest quenching rate till reported. Indeed, a large quenching coefficient KSV = 34.02 x 10− 7 M− 1 and correlation coefficient R2 = 0.9962 in KSV plot have been elucidated with limit of detection (LOD) = 0.7544 ppb. The possible ways of luminescence quenching are successfully explained by the combination of Photoinduced Electron Transfer (PET) and Resonance Energy Transfer (RET) mechanisms. Additionally, the Density Functional Theory (DFT) calculations have been employed to support the experimental results. Cu3(BTC)2 fully demonstrates the power of a multi component MOF, which provides a feasible pathway for the design of novel material towards fast responding luminescence sensing and photocatalytic degradation of pollutants.

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