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

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.

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Sensitive and selective determination of peptides, PG and PGP, using a novel fluorogenic reagent 4-chlorobenzene-1,2-diol

Chemical Papers ◽

10.1515/chempap-2015-0057 ◽

2015 ◽

Vol 69 (4) ◽

Cited By ~ 1

Author(s):

Hasina Yasmin ◽

Mohammed Shafikur Rahman ◽

Takayuki Shibata ◽

Tsutomu Kabashima ◽

Masaaki Kai

Keyword(s):

Reaction Time ◽

Linear Relationship ◽

Fluorescence Intensity ◽

Sodium Periodate ◽

Selective Detection ◽

Fluorometric Method ◽

Reaction Conditions ◽

Fluorescent Signal ◽

Selective Determination

AbstractA novel fluorometric method was developed for the sensitive and selective detection of Pro-Gly (PG) and Pro-Gly-Pro (PGP) using 4-chlorobenzene-1,2-diol (4-CBD) as a fluorogenic reagent. The reaction was performed at 37°C for 30 min in the presence of a borate buffer (pH 7.0) and sodium periodate. The resulting fluorescence intensity was measured using a spectrofluorometer with excitation and emission wavelengths of 450 nm and 535 nm. To obtain a stable fluorescent signal and maximise its intensity, different reaction conditions such as the concentrations of the reagents, the reaction time, and the pH were optimised. Under the optimised conditions, a linear relationship was obtained between fluorescence intensity and peptide concentrations from 1.0-40.0 μmol L

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A Ratiometric Fluorescent Probe Based on Carbon Dots and Bimetallic Nanoclusters for the Assay of Copper Gluconate and Copper Sulfate

NANO ◽

10.1142/s1793292021501149 ◽

2021 ◽

pp. 2150114

Author(s):

Yucong Fan ◽

Weihua Yu ◽

Yue Hu ◽

Yunwen Liao ◽

Xiaohui Jiang ◽

...

Keyword(s):

Fluorescent Probe ◽

Carbon Dots ◽

Limit Of Detection ◽

Molar Ratio ◽

Cupric Sulfate ◽

Selective Determination ◽

Bimetallic Nanoclusters ◽

One Step ◽

The One

Doping Ag-enhanced and glutathione-stabilized Au nanoclusters (GSH–Ag/AuNCs) were prepared by the one-step ultraviolet radiation combined with microwave heating method. The effects of the molar ratio of Au–Ag and different types of energy suppliers on the fluorescent performance of GSH–Ag/AuNCs were studied in detail. After that, a new ratio fluorescent probe (RF-probe) based on the mixing of GSH–Ag/AuNCs with carbon dots (CDs) was designed for sensitive and selective determination of copper gluconate (CG) and cupric sulfate (CS). For the CDs–GSH–Ag/AuNCs RF-probe, the fluorescence (FL) of CDs (at 440[Formula: see text]nm) and that of alloy nanoclusters (NCs) (at 605[Formula: see text]nm) were, respectively, unaffected and strongly quenched in the presence of CG/CS at [Formula: see text][Formula: see text]nm coming from the dynamic quenching process. Corresponding linear ranges and limit of detection (LOD) of the RF-probe for the CG/CS assay were estimated to be 0.17–6.20/0.17–5.62[Formula: see text][Formula: see text]mol/L and 16.80/15.95[Formula: see text]nmol/L, respectively. Furthermore, the proposed RF-probe was successfully used for the assays of CG in CG tablets and CG additive, and CS in infant formula and CS additive, respectively.

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Highly Luminescent and Biocompatible P and N Co-Doped Passivated Carbon Nanodots for the Sensitive and Selective Determination of Rifampicin Using the Inner Filter Effect

Materials ◽

10.3390/ma13102275 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2275 ◽

Cited By ~ 2

Author(s):

Baraa Al-Hashimi ◽

Heshu Sulaiman Rahman ◽

Khalid Mohammad Omer

Keyword(s):

Limit Of Detection ◽

Low Cost ◽

Fluorescence Emission ◽

Inner Filter Effect ◽

Single Step ◽

Carbon Nanodots ◽

Pharmaceutical Dosage Forms ◽

Selective Determination ◽

Filter Effect

The determination of rifampicin in pharmaceutical dosage forms using a rapid, sensitive, selective, biocompatible, and low-cost method is of vital importance in the pharmaceutical analysis field to ensure its concentration is within the effective range when administered. In this study, nitrogen-and-phosphorous-doped carbon nanodots (CNDs) were prepared using a single-step hydrothermal method with ciprofloxacin as the starting material. The CNDs showed a highly intense blue fluorescence emission centered at 450 nm, with a photoluminescence quantum yield of about 51%. Since the absorption of rifampicin was the same as the excitation spectrum of CNDs, inner filter effect (IFE) quenching occurred and it was used as a successful detection platform for the analysis of rifampicin in capsules. The detection platform showed a dynamic linear range from 1 to 100 μM (R2 = 0.9940) and the limit of detection was 0.06 μM (when S/N = 3). The average spike recovery percentage for rifampicin in the capsule samples was 100.53% (n = 5). Moreover, the sub-chronic cytotoxicity of CNDs was evaluated on healthy male mice (Balb/c) drenched with different amounts of CNDs (10 and 50 mg/kg). During this study period, no mortalities or toxicity signs were recorded in any of the experimental subjects. Based on the cytotoxicity experiment, the proposed nano-probe is considered safe and biocompatible.

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One-Pot Hydrothermal Synthesis of Carbon Dots as Fluorescent Probes for the Determination of Mercuric and Hypochlorite Ions

Nanomaterials ◽

10.3390/nano11071831 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1831

Author(s):

Hsin Lee ◽

Yen-Chang Su ◽

Hsiang-Hao Tang ◽

Yu-Sheng Lee ◽

Jan-Yee Lee ◽

...

Keyword(s):

Fluorescence Intensity ◽

Fluorescent Probes ◽

Carbon Dots ◽

Limit Of Detection ◽

Tap Water ◽

Fluorescence Emission ◽

Emission Spectra ◽

Excitation Wavelength ◽

One Pot ◽

Fluorescence Emission Spectra

Nitrogen and sulfur codoped carbon dots (NSCDs) were synthesized via a one-pot hydrothermal method, and citric acid, ethylenediamine, and methyl blue were used as precursors. The obtained NSCDs were spherical with an average size of 1.86 nm. The fluorescence emission spectra of the NSCDs were excitation independent and emitted blue fluorescence at 440 nm with an excitation wavelength at 350 nm. The quantum yield of the NSCDs was calculated to be 68.0%. The NSCDs could be constructed as fluorescent probes for highly selective and sensitive sensing mercuric (Hg2+) and hypochlorite (ClO−) ions. As the addition of Hg2+ or ClO− ions to the NSCDs, the fluorescence intensity was effectively quenched due to dynamic quenching. Under the optimal conditions, the linear response of the fluorescence intensity ranged from 0.7 μM to 15 μM with a detection limit of 0.54 μM and from 0.3 μM to 5.0 μM with a limit of detection of 0.29 μM for Hg2+ and ClO− ions, respectively. Finally, the proposed method was successfully used for quantifying Hg2+ and ClO− ions in spiked tap water samples.

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Novel palladium(II) selective membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc2009555 ◽

2010 ◽

Vol 75 (5) ◽

pp. 563-575 ◽

Cited By ~ 1

Author(s):

Moslem Mohammadi ◽

Mehdi Khodadadian ◽

Mohammad K. Rofouei

Keyword(s):

Limit Of Detection ◽

Membrane Electrode ◽

Aqueous Samples ◽

Selective Determination ◽

Poly Vinyl Chloride ◽

Selective Membrane ◽

Ph Range ◽

Palladium Content ◽

Methyl Benzene

A plasticized poly(vinyl chloride) membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol (L) for highly selective determination of palladium(II) (in PdCl42– form) is developed. The electrode showed a good Nernstian response (29.6 ± 0.4 mV per decade) over a wide concentration range (3.1 × 10–7 to 1.0 × 10–2 mol l–1). The limit of detection was 1.5 × 10–7 mol l–1. The electrode has a response time of about 20 s, and it can be used for at least 2 months without observing any considerable deviation from Nernstian response. The proposed electrode could be used in the pH range of 2.5–5.5. The practical utility of the electrode has been demonstrated by its use for the estimation of palladium content in aqueous samples.

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Synthesis of Fluorescent Carbon Dots and Their Application in Ascorbic Acid Detection

Molecules ◽

10.3390/molecules26051246 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1246

Author(s):

Tengfei Wang ◽

Hui Luo ◽

Xu Jing ◽

Jiali Yang ◽

Meijun Huo ◽

...

Keyword(s):

Ascorbic Acid ◽

Fluorescence Intensity ◽

Carbon Dots ◽

Ph Dependence ◽

Scale Up ◽

Water Soluble ◽

Jujube Fruit ◽

Fluorescent Carbon Dots ◽

Fluorescent Carbon

Water-soluble fluorescent carbon dots (CDs) were synthesized by a hydrothermal method using citric acid as the carbon source and ethylenediamine as the nitrogen source. The repeated and scale-up synthetic experiments were carried out to explore the feasibility of macroscopic preparation of CDs. The CDs/Fe3+ composite was prepared by the interaction of the CDs solution and Fe3+ solution. The optical properties, pH dependence and stability behavior of CDs or the CDs/Fe3+ composite were studied by ultraviolet spectroscopy and fluorescence spectroscopy. Following the principles of fluorescence quenching after the addition of Fe3+ and then the fluorescence recovery after the addition of asorbic acid, the fluorescence intensity of the carbon dots was measured at λex = 360 nm, λem = 460 nm. The content of ascorbic acid was calculated by quantitative analysis of the changing fluorescence intensity. The CDs/Fe3+ composite was applied to the determination of different active molecules, and it was found that the composite had specific recognition of ascorbic acid and showed an excellent linear relationship in 5.0–350.0 μmol·L−1. Moreover, the detection limit was 3.11 μmol·L−1. Satisfactory results were achieved when the method was applied to the ascorbic acid determination in jujube fruit. The fluorescent carbon dots composites prepared in this study may have broad application prospects in a rapid, sensitive and trace determination of ascorbic acid content during food processing.

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Selective determination of Ag+ using Salecan derived nitrogen doped carbon dots as a fluorescent probe

Materials Science and Engineering C ◽

10.1016/j.msec.2017.04.007 ◽

2017 ◽

Vol 77 ◽

pp. 508-512 ◽

Cited By ~ 13

Author(s):

Junjian Li ◽

Gancheng Zuo ◽

Xiaoliang Qi ◽

Wei Wei ◽

Xiaohao Pan ◽

...

Keyword(s):

Fluorescent Probe ◽

Carbon Dots ◽

Selective Determination ◽

Nitrogen Doped ◽

Doped Carbon Dots ◽

Nitrogen Doped Carbon

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Aminophenol-based carbon dots with dual wavelength fluorescence emission for determination of heparin

Microchimica Acta ◽

10.1007/s00604-016-2009-y ◽

2016 ◽

Vol 184 (1) ◽

pp. 187-193 ◽

Cited By ~ 30

Author(s):

Runxia Wang ◽

Xiufang Wang ◽

Yimin Sun

Keyword(s):

Carbon Dots ◽

Fluorescence Emission ◽

Dual Wavelength

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Thin Layer Chromatographic Determination of Citrinin

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/62.1.201 ◽

1979 ◽

Vol 62 (1) ◽

pp. 201-202 ◽

Cited By ~ 2

Author(s):

Robert D Stubblefield

Keyword(s):

Acetic Acid ◽

Thin Layer ◽

Linear Relationship ◽

Silica Gel ◽

Coefficient Of Variation ◽

Ethylenediaminetetraacetic Acid ◽

Limit Of Detection ◽

Chromatographic Determination ◽

Tlc Plates

Abstract Clearly defined zones of citrinin can be obtained on thin layer chromatographic (TLC) plates and measured by fluorodensitometry. Silica gel plates were prepared as a slurry with aqueous 0.05M Na2EDTA (ethylenediaminetetraacetic acid), spread at 0.5 mm wet thickness, and activated at 105°C for 1 hr. Plates were developed in acetic acid-benzene (5+95). The limit of detection was 10 ng citrinin/zone. Densitometric analysis (365 nm excitation, 505 nm emission) revealed that a linear relationship exists for levels of 10 ng to at least 100 ng/zone wtih a coefficient of variation of ±5%.

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