A ratiometric fluorescence strategy based on polyethyleneimine surface-modified carbon dots and Eosin Y for ultrasensitive determination of protamine and trypsin.

The Analyst ◽  
2022 ◽  
Author(s):  
Wenying Sun ◽  
Feng Zhang ◽  
Mengke Wang ◽  
Nan Wang ◽  
Guannan Wang ◽  
...  
Keyword(s):  
Electrostatic Interaction ◽  
Carbon Dots ◽  
Detection System ◽  
Fluorescence Emission ◽  
Eosin Y ◽  
Ratiometric Fluorescence ◽  
Surface Modified ◽  
Emission Detection ◽  
Positively Charged

In this work, we established a novel and ultrasensitive dual-signal fluorescence emission detection system of protamine and trypsin based on the electrostatic interaction between polyethyleneimine (PEI) surface-modified positively charged carbon...

Determination of L-ascorbic Acid by Carbon Quantum Dot/Eosin Y Ratiometric Fluorescence Probe

2020 ◽  
Vol 41 (3) ◽  
pp. 331-338
Author(s):  
武文波 WU Wen-bo ◽  
张越诚 ZHANG Yue-cheng ◽  
李承佳 LI Cheng-jia ◽  
马红燕 MA Hong-yan ◽  
杨晓军 YANG Xiao-jun
Keyword(s):  
Ascorbic Acid ◽  
Quantum Dot ◽  
Fluorescence Probe ◽  
Eosin Y ◽  
Ratiometric Fluorescence ◽  
Carbon Quantum Dot

scholarly journals Validated Analytical Spectrofluorimetric Method for Quantitation of Diphenhydramine HCl in Commercial Dosage Forms

2018 ◽  
Vol 1 (4) ◽  
pp. 12-26
Author(s):  
Syed Najmul Hejaz Azmi ◽  
Aisha Al-Mahroqi ◽  
Khoula Al-Mamari ◽  
Shaima Al-Shukaili
Keyword(s):  
Dynamic Range ◽  
Fluorescence Emission ◽  
Reference Method ◽  
Pharmaceutical Formulations ◽  
Ion Pair ◽  
Ratio Method ◽  
Eosin Y ◽  
Stoichiometric Ratio ◽  
Buffer Solution

Diphenhydramine HClis a weakly fluorescent drug having tertiary amine group forming ion pair complex with eosin Y in dichloromethane at pH 5 in disodium hydrogen phosphate-citric acid buffer solution. The complex formation was the basis for the development of new analytical method for determination of active diphenhydramine in pharmaceutical formulations. The stoichiometric ratio between diphenhydramine and eosin Y was studied by mole ratio method and found to be 2:1. The ion-pair complex showed maximum fluorescence emission intensity at 554 nm with excitation at 259 nm. The linear dynamic range was obtained in the concentration range of 2-22 µg mL-1 with a linear equation of FI = 0.361 + 13.675 C. The apparent Gibb’s free energy (ΔGº) was calculated and found to be -80.783 KJ mol-1, confirmed the feasibility of the reaction. The proposed method was successfully applied to the determination of diphenhydramine HCl in pharmaceutical formulations and in good agreement with the reference method.

A Novel Fluorescent Nanoswitch Based on Carbon Dots for Sensitive Detection of Hg2+ and I−

NANO ◽  
2017 ◽  
Vol 12 (02) ◽  
pp. 1750024 ◽  
Author(s):  
Xiqing Liu ◽  
Xiao Wei ◽  
Yeqing Xu ◽  
Hongji Li ◽  
Kai Lu ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Fluorescence Intensity ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Hydrothermal Process ◽  
Fluorescence Emission ◽  
Selective Determination ◽  
Fluorescence Switching ◽  
Interfering Ions

In this paper, a novel fluorescent nanoswitch based on carbon dots (CDs) was developed for the sensitive and selective determination of Hg[Formula: see text] and I[Formula: see text]. The CDs were obtained by simple hydrothermal process and had a strong fluorescence emission at 440[Formula: see text]nm. The fluorescence of the CDs can be selectively quenched by Hg[Formula: see text] ion, and then the I[Formula: see text] was added into the system, which can interact with Hg[Formula: see text] and recover fluorescence of the CDs. Under optimal conditions, the quenching fluorescence intensity on addition of Hg[Formula: see text] has obtained a satisfactory linear relationship covering the linear range of 0–50[Formula: see text][Formula: see text]M with the linear relationship ([Formula: see text]), and the limit of detection is 0.047[Formula: see text][Formula: see text]M. The additions of I[Formula: see text] could lead to the fluorescence intensity of the solution of CDs and Hg[Formula: see text] (50[Formula: see text][Formula: see text]M) recover rapidly, which is linearly related ([Formula: see text]) to the concentration of I[Formula: see text] in the range from 0 to 70[Formula: see text][Formula: see text]M, the detection limit for I[Formula: see text] was calculated to be 0.084[Formula: see text][Formula: see text]M. Moreover, the developed method to detect Hg[Formula: see text] and I[Formula: see text] was evaluated in real examples, and the fluorescence switching can sensitively and selectively detect Hg[Formula: see text] and I[Formula: see text] over some potentially interfering ions, the recoveries were up to 97.8–107.0% and 96.7–106.6%, respectively.

scholarly journals Ratiometric fluorescence probe of Cu2+ and biothiols by using carbon dots and copper nanoclusters

RSC Advances ◽  
2021 ◽  
Vol 11 (53) ◽  
pp. 33662-33674
Author(s):  
Ning Zhao ◽  
Jianqiang Song ◽  
Zheng Huang ◽  
Xiuying Yang ◽  
Yousheng Wang ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Fluorescent Probe ◽  
Carbon Dots ◽  
Fluorescence Probe ◽  
Ratiometric Fluorescence ◽  
Copper Nanoclusters ◽  
Dual Mechanism ◽  
Fluorescent Carbon Dots ◽  
Ratiometric Fluorescent Probe

A dual-mechanism ratiometric fluorescent probe based on N-doped yellow fluorescent carbon dots (y-CDs) and blue fluorescent copper nanoclusters (CuNCs) was established for the first simultaneous determination of Cu2+ and biothiols.

scholarly journals Terbium Functionalized Schizochytrium-Derived Carbon Dots for Ratiometric Fluorescence Determination of the Anthrax Biomarker

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1234 ◽  
Author(s):  
Lina Zhang ◽  
Zhanwei Wang ◽  
Jingbo Zhang ◽  
Changliang Shi ◽  
Xiaoli Sun ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Dipicolinic Acid ◽  
Green Emission ◽  
Ratiometric Fluorescence ◽  
Green Method ◽  
Lake Water Sample ◽  
Bacillus Anthracis Spores ◽  
Anthrax Spores ◽  
Emission Effect

Efficient and instant detection of biological threat-agent anthrax is highly desired in the fields of medical care and anti-terrorism. Herein, a new ratiometric fluorescence (FL) nanoprobe was elaborately tailored for the determination of 2,6-dipicolinic acid (DPA), a biomarker of anthrax spores, by grafting terbium ions (Tb3+) to the surface of carbon dots (CDs). CDs with blue FL were fabricated by a simple and green method using schizochytrium as precursor and served as an FL reference and a supporting substrate for coordination with Tb3+. On account of the absorbance energy transfer emission effect (AETE), green emission peaks of Tb3+ in CDs-Tb nanoprobe appeared at 545 nm upon the addition of DPA. Under optimal conditions, good linearity between the ratio FL intensity of F545/F445 and the concentrations of DPA was observed within the experimental concentration range of 0.5–6 μM with the detection limit of 35.9 nM, which is superior to several literature studies and significantly lower than the infectious dosage of the Bacillus anthracis spores. Moreover, the CDs-Tb nanoprobe could sensitively detect DPA in the lake water sample. This work offers an efficient self-calibrating and background-free method for the determination of DPA.

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