scholarly journals 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 ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2275 ◽  
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.

Selective determination of acetone by carbon nanodots based on inner filter effect

2019 ◽  
Vol 216 ◽  
pp. 290-295 ◽  
Author(s):  
Liman Sai ◽  
Xingyang Wang ◽  
Quanhong Chang ◽  
Wangzhou Shi ◽  
Lei Huang
Keyword(s):  
Inner Filter Effect ◽  
Carbon Nanodots ◽  
Selective Determination ◽  
Filter Effect

UV-emitting polyelectrolyte-modified MoS2 quantum dots for selective determination of nitrophenol in water samples based on inner filter effect

2020 ◽  
Vol 98 (5) ◽  
pp. 222-227
Author(s):  
Keke Ning ◽  
Guoqiang Xiang ◽  
Cuicui Wang ◽  
Jingxing Wang ◽  
Xiaohong Qiao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Water Samples ◽  
Sodium Molybdate ◽  
Inner Filter Effect ◽  
Pond Water ◽  
Emission Peak ◽  
Selective Determination ◽  
Uv Emission ◽  
Filter Effect

In this work, poly(sodium 4-styrenesulfonate) (PSS) modified molybdenum disulfide quantum dots (MoS2-PSS QDs) were synthesized via a simple hydrothermal method using l-cysteine and anhydrous sodium molybdate as precursors and PSS as a modification reagent, and a selective and sensitive fluorescent sensing method for the determination of p-nitrophenol (p-NP) based on their UV emission was developed. The obtained MoS2-PSS QDs have an obvious UV emission peak (390 nm) with quantum yield of 5.13%. The strong absorption peak of p-NP at 400 nm has large spectral overlap with the UV emission peak (390 nm) of MoS2-PSS QDs. Because of this p-NP absorption, the fluorescence of MoS2-PSS QDs at 390 nm is quenched with the introduction of p-NP via the inner filter effect (IFE) and the decreased fluorescence intensity was linearly proportional to the p-NP concentration in the range of 1–20 μmol/L, leading to a detection limit of 0.13 μmol/L for p-NP. The MoS2 QDs-based fluorescent probe for p-NP is sensitive and selective and was successfully applied in the determination of p-NP in the pond water samples with satisfactory results.

scholarly journals Development of membrane electrodes for selective determination of lisinopril in pharmaceuticals

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah
Keyword(s):  
Enzyme Inhibitor ◽  
Limit Of Detection ◽  
Low Cost ◽  
Ion Pairs ◽  
Standard Addition ◽  
Phosphomolybdic Acid ◽  
Selective Determination ◽  
Accuracy And Precision ◽  
Selective Membrane

Abstract Background Lisinopril (LNP) is an angiotensin-converting enzyme inhibitor used as anti-hypertensive, cardiovascular, in anti-prophylactic and anti-diabetic nephropathy drug. Development of two new, simple, low cost, and selective membrane-based ion-selective electrodes has been proposed for the determination of LNP in pharmaceuticals. Methods The electrodes are based on poly(vinyl)chloride membrane doped with LNP-phosphotungstic acid (LNP-PTA) and LNP-phosphomolybdic acid (LNP-PMA) ion-pairs as molecular recognition materials. Results The developed LNP-PTA and LNP-PMA electrodes are applicable for the determination of LNP over the linear range of 5 × 10−5–2.4 × 10−3 mol l−1. The working pH ranges to measure potentials were 2.5 to 6.4 and 2.3 to 6.0 for LNP-PTA and LNP-PMA ISEs, respectively. The electrodes displayed the rapid Nernstian responses as revealed by the values of slopes 55.06 and 52.39 mV/decade, with limit of detection (LOD) values of 1.2 × 10−5 and 1.18 × 10−5 mol l−1 for LNP-PTA and LNP-PMA electrodes, respectively. The limits of quantitation (LOQ) values have also been calculated for both the electrodes. The developed electrodes have potential stability for up to 1 month and emerged as highly selective for the determination of LNP over other spiked ions and compounds. Conclusions The proposed electrodes have been validated and found that they are suitable for the determination of LNP in pharmaceuticals in pure form and in dosage forms. The results obtained in the analysis of LNP using proposed electrodes have been compared statistically with reference method’s results to assess the accuracy and precision. Robustness and ruggedness of the developed electrodes have also been checked and found satisfactory. The recovery studies have been performed by standard addition procedure to assess the role of excipients in tablets containing LNP and the results obtained are satisfactory.

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.

Nitrogen and chlorine dual-doped carbon nanodots for determination of curcumin in food matrix via inner filter effect

2019 ◽  
Vol 280 ◽  
pp. 195-202 ◽  
Author(s):  
Qin Hu ◽  
Lu Gao ◽  
Sheng-qi Rao ◽  
Zhen-quan Yang ◽  
Tao Li ◽  
...  
Keyword(s):  
Inner Filter Effect ◽  
Carbon Nanodots ◽  
Food Matrix ◽  
Filter Effect

scholarly journals Sensitive and selective determination of tetracycline in milk based on sulfur quantum dot probes

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22960-22968
Author(s):  
Haixin Lu ◽  
Hanqiang Zhang ◽  
Yufei Li ◽  
Feng Gan
Keyword(s):  
Surface Modification ◽  
Quantum Dot ◽  
Fluorescent Probe ◽  
Inner Filter Effect ◽  
Static Quenching ◽  
Selective Determination ◽  
Quenching Effect ◽  
Filter Effect ◽  
First Time

A SQD-based fluorescent probe was applied to detect TC based on the inner filter effect (IFE) and static quenching effect (SQE) without any extra surface modification for the first time.

A Carbon Nanodots-Based Fluorescent Turn-On Probe for Iodide

2015 ◽  
Vol 68 (10) ◽  
pp. 1479 ◽  
Author(s):  
Qi Wang ◽  
Yuehuan Wu
Keyword(s):  
Limit Of Detection ◽  
Rapid Determination ◽  
Low Cost ◽  
Good Health ◽  
Food Chains ◽  
Carbon Nanodots ◽  
Competitive Reaction ◽  
Turn On ◽  
Excellent Selectivity

The human body requires iodine to develop and maintain proper metabolic balance. Worldwide, iodine deficiency affects two billion people and is the leading preventable cause of intellectual disability. Small amounts of iodine are needed for good health. However, large doses can eventually cause iodide goitre, hypothyroidism or myxedema. Children are especially sensitive to the effects of iodine. Because humans can be exposed to iodide via several different food chains, the development of on-site, real-time and reliable sensors for iodide is of great interest to ensure early diagnosis and improve management. We propose here a simple and low cost, yet sensitive and selective fluorescent ‘turn-off-on’ assay for rapid determination of iodide based on a combined carbon nanodots (CDs) and Hg2+ system. The fluorescence of CDs that was quenched by Hg2+ was restored and ‘turned on’ in the presence of iodide, which triggered a competitive reaction among CDs, Hg2+ and iodide. The recovered fluorescence intensity varied linearly with the concentration of iodide in the range of 0.05–5 μmol L–1, with a limit of detection as low as 46 nmol L–1. This approach shows excellent selectivity for iodine over the other anions.

scholarly journals Development of a HPLC-UV method for determination of meloxicam in human plasma and pharmaceutical dosage forms

2014 ◽  
Vol 60 (4) ◽  
pp. 142-145 ◽  
Author(s):  
Csifo Enikő ◽  
Croitoru M. D. ◽  
Fülöp Ibolya ◽  
Muntean Daniela-Lucia
Keyword(s):  
Human Plasma ◽  
Limit Of Detection ◽  
Low Cost ◽  
Extraction Procedure ◽  
Dosage Forms ◽  
Composition Gradient ◽  
Range Limit ◽  
Limit Of Quantification ◽  
Pharmaceutical Dosage Forms

Abstract Objectives: A simple, quick and low cost HPLC-UV method for assay of meloxicam in plasma and pharmaceutical dosage forms was developed. Methods: Separation and assay of meloxicam, using a simple reverse phase HPLC-UV method was achieved using an Agilent Zorbax SB C18 column, with methanol and 1% aqueous solution of glacial acetic acid as mobile phase. Elution was performed with composition gradient, meloxicam being detected at 355 nm with a 5 minutes analysis time. The method was tested on human plasma and pharmaceutical dosage forms. Results: The retention time of the meloxicam was 3,7 minutes. Regression analysis showed good linearity, with correlation coefficient R= 0,9997; linear regression equation: y = 206,1x -77,5 over the 20-2000 ng/ml concentration range. Limit of detection was determined to be 5 ng/ml and limit of quantification was set at 15 ng/ml. The recovery of the analyte in human plasma was low: 30,50%, however it was reproducible, with a coefficient of variation of 4,83%. The analysis of the tablets resulted in a 85,82% of meloxicam compared to the declared concentration. Conclusions: The method proposed is quick, simple and adequate for detecting the meloxicam in human plasma. Although the recovery rate was low, it was reproducible, which leads to the fact, that improving extraction procedure can optimize the method.

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