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1.
Int J Cosmet Sci ; 46(2): 307-317, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38212954

ABSTRACT

OBJECTIVE: External environmental stressors and internal factors have a significant impact on the skin, causing inflammation, aging, reduced immunity and other adverse responses. Dead Sea Water (DSW) is well known for its dermatological benefits and has been widely used in dermatological therapy and skin care for conditions such as psoriasis, atopic dermatitis and photoaging. However, the anti-aging and rejuvenating effects of DSW and the related biological pathways involved, which have attracted increasing attention, are not fully understood. The aim of this study is to investigate the anti-aging and rejuvenating effects of DSW and to explore the related potential biological mechanisms of DSW under different environmental conditions. METHODS: The effects of DSW were investigated using in vitro human dermal cells and reconstructed skin models. Extracellular matrix (ECM) components and the morphological changes at the dermal-epidermal junction (DEJ) in a 3D human skin model were evaluated after DSW treatment. RNA sequencing (RNA-seq) analysis of human dermal fibroblast models after DSW treatment was performed to explore the potential mechanisms of action of DSW under normal and UV stress conditions. RESULTS: The novel findings in this work present the biological functions of DSW, including procollagen-1 and elastin secretion, hemidesmosome increase and the epidermal basal cell regeneration. In addition, GO, KEGG and Reactome analyses reveal the activation of pathways related to ion transmembrane transporter activity, ECM component biosynthesis, senescence-associated secretory phenotype (SASP), DNA repair and autophagy, which are associated with the anti-aging activities of DSW. CONCLUSION: Our work provides new perspectives for understanding the anti-aging and rejuvenating effects and mechanisms of DSW. The new findings also provide a theoretical basis for the further development of age-related strategies.


OBJECTIF: Les facteurs de stress environnementaux externes et les facteurs internes ont un impact significatif sur la peau, provoquant une inflammation, le vieillissement, une baisse de l'immunité et d'autres réactions indésirables. L'eau de la mer Morte est bien connue pour ses bienfaits dermatologiques, et a été largement utilisée dans le traitement dermatologique et les soins de la peau pour des affections telles que le psoriasis, la dermatite atopique et le photovieillissement. Cependant, les effets antivieillissement et rajeunissants de l'eau de la mer Morte et les voies biologiques connexes impliquées, qui font l'objet d'une attention croissante, ne sont pas entièrement compris. L'objectif de cette étude est d'étudier les effets antivieillissement et rajeunissants de l'eau de la mer Morte, et d'étudier les mécanismes biologiques potentiels liés à l'eau de la mer Morte dans différentes conditions environnementales. MÉTHODES: Les effets de l'eau de la mer Morte ont été étudiés à l'aide de cellules dermiques humaines in vitro et de modèles cutanés reconstruits. Les composants de la matrice extracellulaire (MEC) et les changements morphologiques au niveau de la jonction dermo­épidermique (JDE) dans un modèle 3D de peau humaine ont été évalués après le traitement avec de l'eau de la mer Morte. Une analyse de séquençage de l'ARN (ARN­seq) de modèles de fibroblastes dermiques humains après un traitement avec de l'eau de la mer Morte a été réalisée pour étudier les mécanismes d'action potentiels de l'eau de la mer Morte dans des conditions de stress normales et par UV. RÉSULTATS: Les nouveaux résultats de ce travail présentent les fonctions biologiques de l'eau de la mer Morte, y compris la sécrétion de procollagène­1 et d'élastine, l'augmentation des hémidesmosomes et la régénération des cellules basales épidermiques. En outre, les analyses GO, KEGG et Réactome révèlent l'activation de voies liées à l'activité des transporteurs transmembranaires d'ions, à la biosynthèse des composants de la MEC, au phénotype sécrétoire associé à la sénescence (Senescence­Associated Secretory Phenotype, SASP), à la réparation de l'ADN et à l'autophagie, qui sont associés aux activités antivieillissement de l'eau de la mer Morte. CONCLUSION: Notre travail apporte de nouvelles perspectives pour comprendre les effets et les mécanismes antivieillissement et rajeunissants de l'eau de la mer Morte. Les nouveaux résultats fournissent également une base théorique pour le développement ultérieur de stratégies liées à l'âge.


Subject(s)
Dermatitis, Atopic , Skin Aging , Humans , Skin , Epidermis , Seawater , Aging
2.
J Cosmet Dermatol ; 23(1): 244-255, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37430475

ABSTRACT

BACKGROUND: Frankincense volatile oil (FVO) has long been considered a side product in pharmaceutical industry since frankincense of large molecular weight is the prime target. However, the volatile oil recycled in the extract process might contain a series of functional actives, serving as promising ingredients in the cosmetic field. METHODS: Gas chromatography-mass spectrometer was utilized to determine the species and amount of active ingredients in FVO. Subsequently, zebrafish models were used to evaluate pigmentation inhibition, ROS elimination and neutrophil activation. In vitro DPPH test was also conducted to consolidate the anti-oxidation efficacy. Based on the test results, network pharmacology was incorporated, where GO and KEGG enrichment analyses were performed to discover the interrelations between active ingredients. RESULTS: About 40 actives molecules were identified, including incensole, acetate incensole, and acetate incensole oxide. The FVO demonstrated great depigmentation activity by suppressing melanin synthesis, as well as providing free radical scavenging and anti-inflammation effect. In network pharmacology analysis, 192 intersected targets were identified. By enrichment analysis and network construction, a series of whitening signal pathways, and hub genes, containing STAT3,MAPK3,MAPK1 were identified. CONCLUSION: The current study quantified the components of FVO, evaluated its efficacy in skin depigmentation, and give pioneering insights on the possible mechanism. The results confirmed that the FVO could serve as whitening agent in topical uses.


Subject(s)
Frankincense , Oils, Volatile , Animals , Oils, Volatile/pharmacology , Frankincense/chemistry , Zebrafish , Pigmentation , Acetates
3.
Appl Spectrosc ; 77(6): 636-651, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37151096

ABSTRACT

Probes such as carbon dots (C-dots) have extensive and important applications in the quantitative analysis of complex biological and environmental systems. However, the development of probes is often hindered by incomplete selectivity, i.e., a probe that responds to one substance is also prone to respond to coexisting structurally similar substances. Therefore, the above dilemma often leads to be developed as semi-selective probes, so that the development of probes is abandoned halfway. This work shows how a semi-selective probe can enhance selectivity by combining a proper multivariate calibration model. Primarily, we developed a semi-selective fluorescent probe that responded to tetracyclines (TCs) with discarded tobacco leaves. Then, we introduced the multivariate quantitative fluorescence model (QFM) to enhance its selectivity and solve the problem of fluorescence spectral shift. For the determination of chlortetracycline (CTC) with this semi-selective C-dots probe in mineral and lake water samples and compared to the traditional quantitative model, the introduced QFM resulted in an average relative predictive error (ARPE) in mineral water spiked samples decreased from 57.1 to 5.6%, which reduced the ARPE in the lake water spiked samples from 18.1 to 4.7%. The above results show that the QFM-assisted semi-selective probe C-dots strategy (QFMC-dots) can enhance selectivity, and QFMC-dots achieved high-selective and accurate determination of CTC in interfering mineral and lake water samples, with the limit of detection and limit of quantitation of 0.55 and 1.66 µM, respectively. The proposed strategy of enhancing selectivity by introducing a proper multivariate calibration model can reduce the difficulty and increase success rate of developing probes, which can be expected to provide an interesting alternative for the development of probes, especially when encountering semi-selective problems.


Subject(s)
Chlortetracycline , Quantum Dots , Chlortetracycline/analysis , Fluorescent Dyes , Carbon , Spectrometry, Fluorescence/methods , Water , Limit of Detection
4.
Int J Nanomedicine ; 17: 5137-5151, 2022.
Article in English | MEDLINE | ID: mdl-36345507

ABSTRACT

Purpose: Osteosarcoma (OS) is the most common bone cancer with a high risk of metastasis, high growth rate, and poor prognosis. Honokiol (HNK) is a general ingredient of traditional Chinese medicine, with a potential anti-tumor effect. However, HNK is insoluble in water and lacks drug targeting, which limits its clinical application. To improve the OS therapeutic effect of HNK, we used HNK-loaded liposomes modified with hyaluronic acid-phospholipid conjugates (HA-DOPE) to treat OS based on the HA interaction with CD44. Methods: The HNK-loaded liposomes were prepared via thin-film hydration and sonication. HA-DOPE was used to combine the HNK-loaded liposomes (HA-DOPE@Lips/HNK) via sonication and co-extrusion. HA-DOPE@Lips/HNK were characterized with respect to size, zeta potential, polymer dispersity index (PDI), and stability, and transmission electron microscopy was performed. Cellular uptake, cell viability, cell apoptosis, cell cycle, and mitochondrial activity were utilized to evaluate the antitumor effect in vitro. The biodistribution, xenograft tumor growth inhibition, and safety of HA-DOPE@Lips/HNK were evaluated in 143B OS xenograft mice in vivo. Results: The particle size, PDI, and zeta potential of HA-DOPE@Lips/HNK were 146.20±0.26 nm, 0.20±0.01, and -38.45±0.98 mV, respectively. The encapsulation rate and drug loading were 80.14±0.32% and 3.78±0.09%, respectively. HA-DOPE@Lips/HNK could inhibit cell proliferation, cause apoptosis, block the cell cycle and disrupt mitochondrial activity. HA-DOPE@Lips/HNK specially delivered the drug into the tumor and inhibited tumor growth, and showed no obvious toxicity to normal tissues. Conclusion: HA-DOPE@Lips/HNK could deliver HNK into the tumor site and had a good antitumor ability in vitro and in vivo. In addition, HA-DOPE@Lips/HNK increased the antitumor effects of HNK. Thus, it provides a promising nanocarrier to improve drug delivery in OS therapy.


Subject(s)
Bone Neoplasms , Osteosarcoma , Humans , Mice , Animals , Liposomes/therapeutic use , Tissue Distribution , Cell Line, Tumor , Osteosarcoma/pathology , Bone Neoplasms/pathology , Hyaluronic Acid , Polymers/metabolism
5.
Nanomaterials (Basel) ; 12(18)2022 Sep 18.
Article in English | MEDLINE | ID: mdl-36145029

ABSTRACT

Recycling waste biomass into valuable products (e.g., nanomaterials) is of considerable theoretical and practical significance to achieve future sustainable development. Here, we propose a one-pot hydrothermal synthesis route to convert waste tobacco stems into biomass-based N, S-codoped carbon dots (C-dots) with the assistance of carbon black. Unlike most of the previously reported luminescent C-dots, these biomass-based C-dots showed a satisfactory stability, as well as an excitation-independent fluorescence emission at ~520 nm. Furthermore, they demonstrated a pH-dependent fluorescence emission ability, offering a scaffold to design pH-responsive assays. Moreover, these as-synthesized biomass-based C-dots exhibited a fluorescence response ability toward tetracycline antibiotics (TCs, e.g., TC, CTC, and OTC) through the inner filter effect (IFE), thereby allowing for the establishment a smart analytical platform to sensitively and selectively monitor residual TCs in real environmental water samples. In this study, we explored the conversion of waste tobacco stems into sustainable biomass-based C-dots to develop simple, efficient, label-free, reliable, low-cost, and eco-friendly analytical platforms for environmental pollution traceability analysis, which might provide a novel insight to resolve the ecological and environmental issues derived from waste tobacco stems.

6.
Regul Toxicol Pharmacol ; 129: 105114, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35007669

ABSTRACT

Artemisinin-hydroxychloroquine sulfate tablets (AH) are considered a relatively inexpensive and novel combination therapy for treating all forms of malaria, especially aminoquinoline drugs-resistant strains of P.falciparum. We aim to carry out acute and subacute oral toxicity studies in rats to acquire preclinical data on the safety of AH. Acute toxicity was evaluated in Sprague-Dawley (SD) rats at a single dose of 1980, 2970, 4450, 6670, and 10000 mg/kg. A 14-days subacute toxicity was assessed in SD rats at doses of 0, 146, 219, 328, and 429 mg/kg. The median lethal dose (LD50) of acute oral administration of AH in rats is found to be 3119 mg/kg, and toxic symptoms include decreased spontaneous activity, dyspnea, bristling, soft feces, spasticity, and convulsion. Repeated doses of AH have toxic effects on the nervous system, skin, blood system, liver, kidney, and spleen in rats. The main toxic reactions include epilation, emaciation, mental irritability, decreased body weight gain and food consumption, changes in the hematological and biochemical parameters, especially pathological lesions in the liver, kidney, and spleen. The no-observed-adverse-effect level (NOAEL) and lowest-observed-adverse-effect level (LOAEL) of AH are considered to be 219 mg/kg and 328 mg/kg, respectively.


Subject(s)
Antimalarials/toxicity , Artemisinins/toxicity , Hydroxychloroquine/toxicity , Administration, Oral , Animals , Antimalarials/administration & dosage , Antimalarials/pharmacology , Artemisinins/administration & dosage , Artemisinins/pharmacology , Dose-Response Relationship, Drug , Drug Combinations , Female , Hydroxychloroquine/administration & dosage , Hydroxychloroquine/pharmacology , Lethal Dose 50 , Male , No-Observed-Adverse-Effect Level , Random Allocation , Rats , Rats, Sprague-Dawley , Toxicity Tests, Acute , Toxicity Tests, Subacute
7.
Anal Chim Acta ; 1191: 339269, 2022 Jan 25.
Article in English | MEDLINE | ID: mdl-35033278

ABSTRACT

The recycling and reutilization of biomass wastes are significant for environmental protection and sustainable development. Recently, there have many studies on utilizing biomass wastes to produce carbon dots. Whereas, the spectrum shift effect that occurs in the quantitative application of carbon dots as fluorescent probes limits the accuracy of the quantitative analysis. In this work, waste tobacco leaves were used as the carbon source for synthesizing a novel carbon dots (CDs(WTL)) through a facile hydrothermal method. The CDs(WTL) possess a series of excellent properties, including good water solubility, well stability, and high fluorescence quantum yield. The fluorescent intensity of the CDs(WTL) can be quenched by tetracycline (TC) obviously, but there is a spectrum shift. In order to use the CDs(WTL) as fluorescent probes to quantify TC with higher accuracy, a quantification fluorescence model (QFM) was introduced to overcome this spectrum shift effect that often occurs. The coefficient of determination (R2) of traditional quantification model (TQ), partial least squares (PLS), and QFM are 0.9672, 0.9834, and 0.9991, respectively; the average relative predictive error (ARPE) of TQ, PLS, and QFM are 8.8%, 4.5%, and 3.9% for the spiked water samples, and 21.9%, 22.0%, and 2.9% for spiked tablet samples, respectively. The obtained results suggest that QFM is more accurate than PLS and TQ for the TC detection. By utilizing QFM, the spike recoveries (mean ± standard deviation) in three kinds of real tablet samples produced by different manufacturers are 98.9 ± 3.6%, 102.5 ± 6.2%, and 98.5 ± 2.7%, respectively; the spike recovery in river water samples is 99.4 ± 5.0%. In addition, high performance liquid chromatography (HPLC) was used as a reference method, the F and t tests suggest that there are no significant differences on the precision and accuracy between QFM and HPLC methods.


Subject(s)
Carbon , Quantum Dots , Chemometrics , Fluorescent Dyes , Plant Leaves , Spectrometry, Fluorescence , Tetracycline , Nicotiana
8.
J Sep Sci ; 43(13): 2718-2727, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32250027

ABSTRACT

The high selectivities of liquid chromatography and mass spectrometry make liquid chromatography-mass spectrometry one of the most popular tools for quantitative analysis in complex chemical, biological, and environmental systems, while the potential mathematical selectivity of liquid chromatography-mass spectrometry is rarely investigated. This work discussed the mathematical selectivity of liquid chromatography-mass spectrometry by three-way calibration based on the trilinear model, with an application to quantitative analysis of coeluting aromatic amino acids in human plasma. By the trilinear decomposition of the constructed liquid chromatography-mass spectrometry-sample trilinear model and individual regression of the decomposed relative intensity versus concentration, the proposed three-way calibration method successfully achieved quantitative analysis of coeluting aromatic amino acids in human plasma, even in the presence of uncalibrated interferent(s) and a varying background. This analytical method can ease the requirements for sample preparation and complete chromatographic separation of components, reduce the use of organic solvents, decrease the time of chromatographic separation, and increase the peak capacity of liquid chromatography-mass spectrometry. As a "green analytical method", the liquid chromatography-mass spectrometry three-way calibration method can provide a promising tool for direct and fast quantitative analysis in complex systems containing uncalibrated spectral interferents, especially for the situation where the coelution problem is difficult to overcome.


Subject(s)
Phenylalanine/blood , Tryptophan/blood , Tyrosine/blood , Algorithms , Calibration , Chromatography, Liquid , Humans , Mass Spectrometry , Software
9.
Talanta ; 197: 105-112, 2019 May 15.
Article in English | MEDLINE | ID: mdl-30771910

ABSTRACT

The simultaneous quantitative analysis of intracellular metabolic coenzymes flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) is of interest because they participate in many electron-transfer reactions of metabolism. But, the simultaneous quantitative analysis of FAD and FMN is hard to be achieved by traditional analytical methods. This paper proposes a novel strategy of intrinsic fluorescence coupled with four-way calibration method for simultaneous quantitative analysis of intracellular metabolic coenzymes FAD and FMN. Through mathematical separation, this proposed analytical method efficiently achieved the simultaneous quantitative analysis of metabolic coenzymes FAD and FMN in the cell, despite the fact that uncalibrated spectral interferents coexist in the system. The predicted concentrations of FAD and FMN in the cell are 217.0 ±â€¯6.9 and 155.0 ±â€¯1.7 pmol/106 cells respectively, which were validated by the approved liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. This analytical method with second-order advantage simply requires the cell solution to be diluted by a buffer, it could introduce an interesting analytical strategy for multianalyte direct quantitative analysis in complex biological systems. In addition, we explore the third-order advantage of four-way calibration by a comparative study based on this real fluorescence data. The comparisons indicate that a four-way calibration method can provide higher sensitivity and more resolving power than a three-way calibration method.


Subject(s)
Flavin Mononucleotide/analysis , Flavin-Adenine Dinucleotide/analysis , Fluorescence , Calibration , Chromatography, Liquid , Flavin Mononucleotide/metabolism , Flavin-Adenine Dinucleotide/metabolism , HeLa Cells , Humans , Tandem Mass Spectrometry
10.
Talanta ; 192: 233-240, 2019 Jan 15.
Article in English | MEDLINE | ID: mdl-30348383

ABSTRACT

Probe encapsulated by biologically localized embedding (PEBBLE) has emerged as a new type of sensing technique for complex systems. Generalized ratiometric PEBBLE nanosensors prepared by encapsulating an intensity-based probe and an inert reference dye inside the pores of stable matrix possess advantages of easy synthesis, immunity to interference, lower toxicity, and robustness to variations in probe loading. However, the selection of appropriate reference dyes used in generalized ratiometric PEBBLE nanosensors is a rather difficult task since they should satisfy some stringent requirements. In this contribution, the feasibility of using carbon dots (C-dots) as generic inert references in synthesizing PEBBLE nanosensors was first investigated in detail. And a dual-wavelength monitoring strategy and the quantitative fluorescence model for generalized ratiometric probes (QFMGRP) were adopted to solve the problems brought by the use of carbon dots as inert references. C-dots doped PEBBLE nanosensors (C-PEBBLE nanosensors) for the quantification of NO2- and free Ca2+ were synthesized by encapsulating C-dots and intensity based fluorescence probes (i.e., acriflavine for NO2-, and Rhod-2 for Ca2+, respectively) inside the pores of stable matrix. Experimental results showed that the combination of C-PEBBLEs, the QFMGRP model and the dual-wavelength monitoring strategy achieved accurate quantification of NO2- and the free Ca2+ in real-world samples. Their quantitative results were in good consistence with those determined by HPLC and atomic absorption spectrophotometer, respectively. The strategies proposed in this contribution have generic applicability in the synthesis of PEBBLE nanosensors and their quantitative applications.


Subject(s)
Carbon/chemistry , Fluorescent Dyes/chemistry , Quantum Dots/chemistry , Acriflavine/chemistry , Acrylic Resins/chemistry , Calcium/analysis , Fluorescence , Heterocyclic Compounds, 3-Ring/chemistry , Limit of Detection , Nitrites/analysis , Particle Size , Polymerization , Porosity , Spectrometry, Fluorescence/methods
11.
Hepatol Res ; 48(8): 635-663, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29330919

ABSTRACT

AIM: The aim of this study was to evaluate the surgical safety and effectiveness of laparoscopic hepatectomy (LH) in short- and long-term outcomes compared to open hepatectomy (OH) in patients treated for hepatocellular carcinoma (HCC). METHODS: An electronic search of reports published before August 2017 was carried out to identify comparative studies evaluating LH versus OH for HCC. RESULTS: A total of 5889 patients (2421 underwent LH; 3468 underwent OH) were included in our meta-analysis from 47 studies. Laparoscopic hepatectomies were associated with favorable outcomes in terms of operative blood loss (mean difference [MD], -147.27; 95% confidence interval [CI], -217.00, -77.55), blood transfusion requirement (odds ratio [OR], 0.51; 95% CI, 0.40, 0.65), pathologic resection margins (MD, 0.07; 95% CI, 0.02, 0.12; P = 0.01), R0 resection rate (OR, 1.34; 95% CI, 0.98, 1.84; P = 0.07), and length of hospital stay (MD, -5.13; 95% confidence interval, -6.23, -4.03). There were no differences between the groups in overall survival (OS) at 1 year (OR, 1.41; 95% CI, 1.00, 1.98), 3 years (OR, 1.12; 95% CI, 0.93, 1.36), or 5 years (OR, 1.18; 95% CI, 0.94, 1.46), in disease-free survival (DFS) at 1 (OR, 1.19; 95% CI, 0.94, 1.51), 3 years (OR, 1.07; 95% CI, 0.86, 1.33), or 5 years (OR, 1.13; 95% CI, 0.92, 1.40), or in recurrence (OR, 0.90; 95% CI, 0.74, 1.08). CONCLUSION: Compared to OH, LH is superior in terms of lower intraoperative blood loss and the requirement for blood transfusion, larger pathologic resection margins, increased R0 resection rates, and shorter length of hospital stay. Laparoscopic hepatectomy and OH have similar OS, DFS, and recurrence.

12.
Toxins (Basel) ; 8(5)2016 05 04.
Article in English | MEDLINE | ID: mdl-27153092

ABSTRACT

Periplocosides, which are insecticidal compounds isolated from the root bark of Periploca sepium Bunge, can affect the digestive system of insects. However, the mechanism though which periplocosides induces a series of symptoms remains unknown. In this study, affinity chromatography was conducted by coupling periplocoside E-semi-succinic acid ester with epoxy amino hexyl (EAH) sepharose 4B. Sodium dodecyl sulfonate-polyacrylamide gelelectrophoresis (SDS-PAGE) was performed to analyze the fraction eluted by periplocoside E. Eight binding proteins (luciferin 4-monooxygenase, aminopeptidase N, aminopeptidase N3, nicotinamide adenine dinucleotide health (NADH) dehydrogenase subunit 5, phosphatidylinositol 3-phosphate 3-phosphatase myotubularin, actin, uncharacterized family 31 glucosidase KIAA1161, and 2OG-Fe(2) oxygenase superfamily protein) were obtained and identified through liquid chromatography/quadrupole-time of flight-mass spectrometry (LC/Q-TOF-MS) analysis of the midgut epithelium cells of Mythimna separata larvae. Aminopeptidase N and N3 are potential putative targets of periplocosides. This study establishes the foundation for further research on the mechanism of action and target localization of periplocosides in agricultural pests.


Subject(s)
Carrier Proteins/isolation & purification , Insect Proteins/isolation & purification , Lepidoptera , Animals , Chromatography, Affinity , Esters , Insecticides , Intestines/chemistry , Larva , Microvilli , Oligosaccharides , Pregnenes
13.
Anal Chim Acta ; 921: 38-45, 2016 05 19.
Article in English | MEDLINE | ID: mdl-27126788

ABSTRACT

PEBBLE (probe encapsulated by biologically localized embedding) nanosensor encapsulating an intensity-based fluorescence indicator and an inert reference fluorescence dye inside the pores of stable matrix can be used as a generalized wavelength-ratiometric probe. However, the lack of an efficient quantitative model render the choices of inert reference dyes and intensity-based fluorescence indicators used in PEBBLEs based generalized wavelength-ratiometric probes rather limited. In this contribution, an extended quantitative fluorescence model was derived specifically for generalized wavelength-ratiometric probes based on PEBBLE technique (QFMGRP) with a view to simplify the design of PEBBLEs and hence further extend their application potentials. The effectiveness of QFMGRP has been tested on the quantitative determination of free Ca(2+) in both simulated and real turbid media using a Ca(2+) sensitive PEBBLE nanosensor encapsulating Rhod-2 and eosin B inside the micropores of stable polyacrylamide matrix. Experimental results demonstrated that QFMGRP could realize precise and accurate quantification of free Ca(2+) in turbid samples, even though there is serious overlapping between the fluorescence excitation peaks of eosin B and Ca(2+) bound Rhod-2. The average relative predictive error value of QFMGRP for the test simulated turbid samples was 5.9%, about 2-4 times lower than the corresponding values of partial least squares calibration model and the empirical ratiometric model based on the ratio of fluorescence intensities at the excitation peaks of Ca(2+) bound Rhod-2 and eosin B. The recovery rates of QFMGRP for the real and spiked turbid samples varied from 93.1% to 101%, comparable to the corresponding results of atomic absorption spectrometry.


Subject(s)
Calcium/analysis , Eosine I Bluish/chemistry , Fluorescent Dyes/chemistry , Spectrometry, Fluorescence/methods , Acrylic Resins/chemistry , Eosine I Bluish/administration & dosage , Fluorescent Dyes/administration & dosage , Heterocyclic Compounds, 3-Ring/administration & dosage , Heterocyclic Compounds, 3-Ring/chemistry , Nanotechnology , Nephelometry and Turbidimetry , Particle Size , Porosity
14.
Anal Sci ; 30(4): 489-94, 2014.
Article in English | MEDLINE | ID: mdl-24717659

ABSTRACT

In this work, a simple and practicable method that combines excitation-emission matrix (EEMs) fluorescence with a second-order calibration method based on parallel factor analysis-alternative least-squares (PARAFAC-ALS) algorithm was developed for the direct interference-free determination of indole-3-acetic acid (IAA) in two real systems, coconut water (CW) and coconut milk (CM). Although the excitation and emission profiles of IAA heavily overlapped with that of unknown interferents in the complex real systems, the actual contents and satisfactory recoveries were still obtained successfully. The contents of IAA in CW and CM were 10.8 ± 0.3 and 4.9 ± 0.2 µg mL(-1), respectively, which were consistent with those reported by LC-MS/MS assays in the reference material. The average spike recoveries of IAA in the validation set based on CW and CM were 102.1 ± 3.2 and 98.0 ± 1.9%, respectively. In addition, routine experiments were performed for establishing the validity of the assay to internationally accepted criteria.

15.
Talanta ; 103: 86-94, 2013 Jan 15.
Article in English | MEDLINE | ID: mdl-23200362

ABSTRACT

In this work, with the purpose of developing an effective and inexpensive method, excitation-emission matrix fluorescence data and second-order calibration method based on the self-weighted alternating trilinear decomposition (SWATLD) algorithm were combined for simultaneous determination of 2-naphthoxyacetic acid (NOA) and 1-naphthaleneacetic acid methyl ester (NAAME) in environmental samples, i.e. soil and sewage samples. In order to investigate the prediction quality of the proposed method, different strategies, such as taking spectroscopic measurements in the presence of different matrix interferents and at different fluorescence spectrophotometers, were introduced to build calibration models and comparisons among them were done subsequently. The root-mean-square error of prediction and t-test were used to compare different SWATLD-based calibration models. The limits of detection obtained for NOA and NAAME were 0.36-0.95 ng mL(-1) and 1.32-2.69 ng mL(-1), respectively, for different models. Such a chemometrics-based protocol may possess great potential to be extended as a promising alternative for more practical applications in environment monitoring and for the design of small intelligent and field-portable analytical instruments that rely on statistical discrimination, not complete instrumental separation, of the target analytes even in the presence of unknown and uncalibrated interferences.


Subject(s)
Environmental Monitoring , Models, Statistical , Photochemical Processes , Plant Growth Regulators/analysis , Spectrometry, Fluorescence , Algorithms , Calibration , Limit of Detection , Quality Control , Sewage/analysis , Soil Pollutants/analysis
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