Search

• We obtained satisfactory recoveries, good sensitivity, and non-interfering eletrophoretic analysis. • Our developed system was used to quantify mirtazapine-related drugs in human fluids. • Ultrasensitive analysis of mirtazapine-related drugs was achieved by the proposed system. • The sensitivity was improved to 2700–3900 times by USA-DLLME and PDDAC-mediated CE stacking. • This system has the merits of simplicity, rapidity, separation efficiency, and sensitivity. A simple, rapid, and sensitive technique for measuring mirtazapine and its metabolites enantiomers in human fluids, such as urine and serum, was developed by applying ultrasound-enhanced and surfactant-assisted dispersive liquid–liquid microextraction (USA-DLLME) integrated with poly(diallyldimethylammonium chloride) (PDDAC)-mediated stacking in capillary electrophoresis (CE). The parameters that affect extraction and stacking performance, such as the extraction volume, surfactant types, surfactant concentrations, salt additives, extraction time, solution pH, and background electrolytes, were comprehensively studied and optimized to achieve optimal detection performance. Under optimal extraction conditions (injection of 120 µL of C 2 H 2 Cl 4 into 1 mL of a sample solution containing 0.05 mM Brij-35 at pH 10.0) and separation conditions (0.9% PDDAC, 10 mM phosphate, pH 3.0, and 20 mM dimethyl-β-cyclodextrin), on-line CE stacking of mirtazapine-related chiral drugs was achieved by the two strategies: (i) neutral DM-β-CD sweep low concentrations of DL-NaSSA and (ii) DL-NASSA is stacked by the difference in the viscosity between the PDDAC and sample zone. An approximately 2,800–4000-fold improvement in detection sensitivity was revealed for mirtazapine, N-demethylmirtazapine, and 8-hydroxymirtazapine enantiomers. The linear ranges for the quantification of all analyte enantiomers were 1.2–150 nM, with a coefficient of determination higher than 0.99; the relative standard deviations in the migration time and peak areas for six analytes were less than 1.8% and 5.8%, respectively. The proposed system provided the limits of detection (signal-to-noise ratio of 3) of the six analytes as 0.3–0.5 nM. The recovery of the six separated analytes spiked in urine and serum samples was revealed to be 82.7%–109.5% and 91%–112.8%, respectively. This advanced technique with high sensitivity enhancement factors was successfully employed to analyze mirtazapine and its metabolites enantiomers in urine and serum samples with reliability. [ABSTRACT FROM AUTHOR]

This work proposed a straightforward synthesis of copper nanoclusters (CuNCs) with an emission wavelength of 496 nm and a quantum yield of 2.2% by directly using pepsin as a template with low toxicity NaBH4 and ascorbic acid as reducing agents. The chemical composition and optical properties of the pepsin‐stabilized CuNCs (pepsin‐CuNCs) were well‐characterized by spectroscopy‐related techniques. The pepsin‐CuNCs retained the fluorescence intensity at neutral pH, at 37°C, and in high salinity, proving their suitability in biological systems. Although the pepsin‐CuNCs remained only half of the initial fluorescence intensity after 24 days due to air oxidation, their storage stability was comparable to that of CuNCs reported in the literature. Given that the absorption peaks of hemoglobin overlap the excitation and emission wavelengths of pepsin‐CuNCs, this feature allowed pepsin‐CuNCs to serve as a luminescence turn‐off sensor for sensing hemoglobin through the inner‐filter effect process. The pepsin‐CuNC probe provided a fast (within 1 min) platform for hemoglobin detection with a dynamic quantitative range of 0.1–10 μM and a detection limit of 70 nM. Importantly, the proposed probe was well‐suited to detect hemoglobin in nearly undiluted human urine, demonstrating its great potential for the clinical diagnosis of trace hemoglobin in urine. [ABSTRACT FROM AUTHOR]

High-speed capillary electrophoresis (CE) enables the simple, rapid, and inexpensive analysis of large sets of chiral samples in the pharmaceutical industry. Hence, we developed a novel method for separating enantiomers of d,l -phenothiazines simply and rapidly, based on using poly(diallyldimethylammonium chloride) (PDDAC) as an additive and hydroxypropyl-γ-cyclodextrin (Hp-γ-CD) as a chiral selector in capillary electrophoresis. Adding 0.9% PDDAC to the background electrolyte generated a stable, high, and reversed electroosmotic flow (EOF). Hp-γ-CD not only worked as a complexing agent to increase the chiral resolution between d,l -phenothiazines but also decreased the effective electrophoretic mobility of these drugs. Combining PDDAC and Hp-γ-CD as buffer additives enabled CE to achieve a high-speed enantioseparation of five pairs of d,l -phenothiazines. A decrease in capillary length and an increase in the intensity of the electric field further shortened the separation time. When the background electrolyte contained 0.9% PDDAC, 5 mM Hp-γ-CD, and 75 mM formic acid (pH 3.0), enantioseparation of the d,l -phenothiazines was attained within 230 s by applying a capillary length of 32.5 cm and an electric field of 292 V cm −1 . The limit of detection (LOD) of the d,l -phenothiazines at a signal-to-noise ratio of 3 ranged from 2 to 8 μM. We demonstrated the feasibility of this method by detecting the five pairs of d,l -phenothiazines in urine samples. [ABSTRACT FROM AUTHOR]

We developed a triple-readout probe for colorimetric, fluorescent, and fluorescence-lifetime sensing of alkaline phosphatase (ALP) through the hydrolyzed ascorbic acid phosphate (AAP)–mediated formation of silver nanoparticles (AgNPs) on Ag+-deposited MoS2 quantum dots (QDs). Ag+ ions were self-assembled on a monolayer MoS2 QD surface through the formation of Ag–S bonds. When ALP hydrolyzed AAP in an alkaline buffer, the resultant ascorbic acid (AA) triggered the reduction of the bound Ag+ ions into AgNPs on the MoS2 QD surface. The resultant AgNPs induced an efficient fluorescence quenching of the MoS2 QDs through simultaneous static and dynamic quenching processes, generated an intense surface plasmon resonance peak, and triggered a reduction in the fluorescence lifetime of the MoS2 QDs. Electron microscopy and spectroscopic techniques revealed the successful fabrication of Ag+-deposited MoS2 QDs and the ALP-mediated formation of AgNPs on the MoS2 QD surface. The linear quantification ranges for ALP were 0.05–2.5, 0.1–4, and 1–4 units L−1 in the fluorescent, colorimetric, and fluorescence-lifetime detection modes, respectively. In addition, the proposed probe integrated with an ALP-linked sandwich immunoassay exhibited high sensitivity and selectivity for the fluorescence sensing of rabbit immunoglobulin G with a detection limit of 8 pg mL−1 and linear range of 25–1000 pg mL−1. The sensitivity of the probe is comparable to those of previously reported immunoassays involving ultrasensitive electrochemical detection, hydrogen evolution reactions, or electron spin resonance. The probe integrated with the sandwich assay serves as a promising platform for the detection of target proteins in clinical samples. [ABSTRACT FROM AUTHOR]

Abstract Background Dyslipidaemia has always been regarded as the cornerstone of arteriosclerosis and is related to the pathogenesis of renal insufficiency. However, it is unclear which routinely available lipid parameter is related to urinary albumin to creatinine ratio (UACR). The purpose of this study was to examine the lipid abnormalities associated with UACR in the general population in China. Methods The present study was nested in an ongoing Risk Evaluation of cAncers in Chinese diabetic Individuals: A lONgitudinal (REACTION) study, which was designed to demonstrate the association of abnormal glucose metabolism with the risk of cancer in the Chinese population. This cross-sectional study included 34, 569 subjects (11, 390 males and 23, 179 females) from 8 different regional community cohorts, with an average age of 57.9 years. The UACR data were divided into the

Objectives. To assess the effectiveness and safety of ARW for vascular recanalization in CTO patients. Background. Chronic total occlusion (CTO) of coronary artery accompanied with large branch distal to the occluded segment (

Pituitary stalk interruption syndrome (PSIS) is a rare congenital defect manifesting as various degrees of anterior pituitary hormone deficiency. Scattered familial cases have been found, revealing some genetic variants. However, most of the previous research studies involved an affected sibling, and the gene spectra of the patients’ entire family have rarely been reported. We conducted a study of a family consisting of a PSIS patient with his unaffected sibling and healthy parents of Han Chinese background using whole-genome sequencing. Bioinformatic analysis was carried out, and mutations related to PSIS, single-nucleotide variants (SNVs), insertion-deletion (InDELs), and structural variations (SVs) in all the four samples were filtered. After Sanger sequencing, we confirmed the variants obtained and selected three candidate genes for functional verification. The gene variations in this boy with PSIS and his lineal relatives are reported herein; de novo sequencing revealed that the NBPF9 gene may be involved in the pathogenesis of PSIS.

PD-L1 is a promising therapeutic target in aggressive cancers. However, immune landscapes and cancer hallmarks of human PD-L1+ tumors, as well as their roles in determining therapeutic efficacies are unknown. Here we identified, in detailed studies of gene data regarding 9769 patients of 32 types of human cancers, that PD-L1 could not exclusively represent IFN-γ signature and potentially signified pro-inflammatory myeloid responses in a tumor. PD-L1 heterogeneity endowed by local immune landscapes controlled cancer hallmarks and clinical outcomes of patients. Mechanically, NF-κB signal elicited by macrophage inflammatory responses generated PD-L1+ cancer cells exhibiting capabilities to aggressively survive, support angiogenesis, and metastasize, whereas STAT1 signal triggered by activated T cells induced PD-L1+ cancer cells susceptive to apoptosis. Importantly, PD-L1+ cancer cells generated by macrophages established great resistance to conventional chemotherapy, cytotoxicity of tumor-specific effector T cells, and therapy of immune checkpoint blockade. Therapeutic strategy combining immune checkpoint blockade with macrophage depletion or NF-κB inhibition in vivo effectively and successfully elicited caner regression. Our results provide insight into the functional features of PD-L1+ tumors and suggest that strategies to influence functional activities of inflammatory cells may benefit immune checkpoint blockade therapy. [ABSTRACT FROM AUTHOR]

Abstract Citrate-capped gold nanoparticles (AuNPs) modified with thrombin-binding aptamer are often implemented for colorimetric, fluorescent, and electrochemical detection of thrombin in an aqueous solution. However, researchers have rarely explored the application of fibrinogen-modified AuNPs (F-AuNPs) for thrombin sensing. We present a simple, inexpensive, sensitive, and selective probe for colorimetric assay of thrombin through combining thrombin-induced inclusion of F-AuNPs into Fibrin and F-AuNPs-catalyzed reduction of 4-nitrophenol with an excess amount of NaBH 4. Considering that fibrinogen stabilized citrate-capped AuNPs against a high-ionic-strength buffer, F-AuNPs efficiently catalyzed the NaBH 4 -mediated decrease of yellow 4-nitrophenol to colorless 4-aminophenol. The presence of thrombin converted fibrinogen into fibrin on the nanoparticle surface, leading to the inclusion of nanoparticles into fibrin. The formation of fibrin inhibited that the AuNPs catalyzed the NaBH 4 -mediated reduction of 4-nitrophenol. Consequently, the color of the solution gradually varied from colorless to yellow with increasing thrombin concentration. The proposed system was shown to be accurate in the quantification of small differences in the concentration of human thrombin over the range of 4–60 pM. The lowest detectable concentration of human thrombin by the naked eye was as low as 16 pM. We demonstrated the practical application of the proposed system in quantifying 1–15 nM human thrombin in human plasma. Graphical Abstract Unlabelled Image Highlights • Fibrinogen-capped gold nanoparticles provide excellent catalytic activity. • Fibrin-encapsulated gold nanoparticles exhibit poor catalytic activity. • The proposed system can detect 4–60 pM thrombin with excellent selectivity. • The proposed system can sense 1–15 nM thrombin in human plasma. [ABSTRACT FROM AUTHOR]

Background: Several previous studies have shown that snoring is associated with glucose metabolism and the development of diabetes, but rare study has shown the association between snoring frequency and prediabetes, particularly in China. We hypothesized that individuals who snore might have a higher risk of prediabetes. This study aimed to investigate the association between self-reported snoring and prediabetes in a Chinese population. Methods: A cross-sectional study was performed in three large communities of Beijing from December 2011 to August 2012 by recruiting individuals aged ≥40 years old. All participants were requested to complete a detailed questionnaire and undergo anthropometric measurements. A 75 g oral glucose tolerance test was performed in individuals without diabetes. Blood samples of all participants were collected; blood glucose and blood fat levels were measured. Multivariate logistic regression models were built to assess the association between snoring frequency and prediabetes. Results: A total of 13,592 participants (female: 66.56%; mean age: 56.8 ± 7.9 years; mean body mass index: 25.5 ± 3.4 kg/m2) were included in the final analysis. Of these, 30.9% were diagnosed with prediabetes, while 41.3% and 25.4% had occasional and habitual snoring, respectively. Habitual snoring was associated with an increased risk of prediabetes (odds ratio [OR]: 1.3, 95% confidence interval [CI]: 1.1–1.4, P< 0.001), after adjusting for diabetes and sleep-related confounders in the multivariable models. Habitual snoring was also associated with isolated impaired fasting glucose (IFG; OR: 1.3, 95% CI: 1.0–1.6; P< 0.001) and isolated impaired glucose tolerance (IGT; OR: 1.3, 95% CI: 1.2–1.5; P< 0.001), but not IFG + IGT (OR: 1.1, 95% CI: 0.9–1.4; P = 0.281). When stratified by total cholesterol (TC) levels, this association between habitual snoring and prediabetes was observed only in individuals with TC

Background: Prolonged gonadal hormone deficiency in patients with idiopathic hypogonadotropic hypogonadism (IHH) may produce adverse effects on the endocrine homeostasis and metabolism. This study aimed to compare basal serum adrenocorticotropic hormone (ACTH) and cortisol levels between male IHH patients and healthy controls. Moreover, this study compared the basal hypothalamic-pituitary-adrenal (HPA) axis in patients with and without nonalcoholic fatty liver disease (NAFLD), and also evaluated the relationship between basal HPA axis and NAFLD in male IHH patients. Methods: This was a retrospective case-control study involving 75 Chinese male IHH patients (mean age 21.4 ± 3.8 years, range 17–30 years) and 135 healthy controls after matching for gender and age. All subjects underwent physical examination and blood testing for serum testosterone, luteinizing hormone, follicle-stimulating hormone, ACTH, and cortisol and biochemical tests. Results: Higher basal serum ACTH levels (8.25 ± 3.78 pmol/L vs. 6.97 ± 2.81 pmol/L) and lower cortisol levels (366.70 ± 142.48 nmol/L vs. 452.82 ± 141.53 nmol/L) were observed in male IHH patients than healthy subjects (all p

Background: Type 2 diabetes mellitus (T2DM) has traditionally been considered to affect mainly the elderly; however, the age at diagnosis has gradually reduced in recent years. Although the incidence of young-onset T2DM is increasing, it is still not fully clear the onset characteristics and risk factors of early-onset T2DM. The aim of this study was to describe the initiating characteristics of early-onset T2DM in Chinese patients and evaluate the risk factors for diabetes mellitus. Methods: This cross-sectional controlled study was performed using a questionnaire survey method in outpatients of multiple centers in China. A total of 1545 patients with T2DM with an age at onset of

Background:. Hypertension often persists after adrenalectomy for primary aldosteronism (PA). Many studies have analyzed the outcomes of adrenalectomy for aldosterone-producing adenomas (APA) to identify predictive factors for persistent hypertension. However, differentially expressed genes in persistent postoperative hypertension remain unknown. Our aim was to describe gene expression profile of persistent postoperative hypertension patients with APA. Methods:. In this study, we described and compared gene expression profiles in persistent postoperative hypertension and postoperative normotension in Chinese patients with APA using microarray analysis. Confirmation was performed with quantitative real time-polymerase chain reaction analysis. Bioinformatic analysis (gene ontology analysis, pathway analysis and network analysis) was used for further research. Results:. Microarray analysis identified a total of 99 differentially expressed genes, including 18 up-regulated and 81 down-regulated genes. Among the dysregulated genes were fat atypical cadherin 1 as well as fatty acid binding protein 4 and other genes that have not been previously studied in persistent postoperative hypertension with APA. Bioinformatics analysis indicated that differentially expressed genes were associated with lipid metabolic process, metal ion binding, and cell differentiation. Pathway analysis determined that five pathways corresponded to the dysregulated transcripts. The mRNAs-ncRNAs co-expression network was composed of 49 network nodes and 72 connections between 18 coding genes and 31 noncoding genes. Conclusions:. This study revealed differentially expressed genes in persistent postoperative hypertension with APA and provided a resource of candidate genes for exploration of possible drug targets and prognostic markers.

Objective. To investigate the association between the hypertriglyceridemic waist (HTGW) phenotype and prediabetes in Chinese adults aged 40 years and older. Methods. 12757 adults (4101 men and 8656 women) without diabetes or cardiovascular and cerebrovascular diseases, free of using lipid-modified agents, were enrolled in this cross-sectional study. The HTGW phenotype was defined as elevated serum triglyceride concentrations and enlarged waist circumference. A two-hour post 75 g oral glucose tolerance test was performed in all participants. Multiple logistic regression analysis was used to evaluate the relationship of the HTGW phenotype with prediabetes. Results. Individuals with the HTGW phenotype had a higher adjusted odds ratio (OR: 1.70; 95% CI: 1.48–1.95) of prediabetes than those without the phenotype. There existed a strong relationship of the HTGW phenotype with impaired glucose tolerance (IGT) (OR: 1.83; 95% CI: 1.57–2.13), but not with impaired fasting glucose (IFG) (OR: 0.87; 95% CI: 0.65–1.17). Only women with the HTGW phenotype are significantly associated with the combined IFG and IGT (OR: 1.83; 95% CI: 1.28–2.62). Conclusions. The HTGW phenotype was a useful risk indicator and a practical screening tool to benefit in the early diagnosis and intervention for prediabetes, particularly for IGT and the combined IFG and IGT.

Background: Delayed puberty can result either from constitutional delay of growth and puberty (CDP) or idiopathic hypogonadotropic hypogonadism (IHH). Gonadotropin-releasing hormone (GnRH) stimulation test has been generally accepted as a current method for diagnosing delayed puberty. The objective of this research was to assess the cut-off values and the efficacy of GnRH stimulation test in the diagnosis of delayed puberty in both males and females. Methods: A study of 91 IHH, 27 CDP patients, 6 prepubertal children, and 20 pubertal adults was undertaken. Blood samples were obtained at 0, 30, 60, and 120 min after GnRH administration and the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured. For each parameter, the sensitivities and specificities were estimated, and the receiver operating characteristic (ROC) curves were constructed. Results: The ROC curves indicated that a serum basal LH

Objective. We aim to investigate the long-term benefits of growth hormone (GH) therapy in short stature adolescents and adults with pituitary stalk interruption syndrome (PSIS), which would be beneficial for future clinical applications. Design and Methods. In this study, initial height, final height, total height gain, and GH treatment history were retrospectively investigated in 75 Chinese PSIS patients. We compared height gain between the GH treated cohort and untreated cohort and explored the impact of different GH therapy duration on height gain. Results. For GH treated patients, their final height (SDS) increased from -1.99±1.91 (−6.93~2.80) at bone age (BA) of 11.2 (5.0~17.0) years to -1.47±1.64 (−7.82~1.05) at BA of 16.6 (8.0~18.0) years (P=0.016). And GH treated patients had more height gain than the untreated patients (P

Aim. To investigate incidental adrenal enlargement clinical characteristics and functional status and analyze functional lesion risk factors. Materials and Methods. This retrospective study included 578 patients with adrenal imaging features showing enlargement. Incidental adrenal enlargement cases (78) were considered eligible. Demographics, functional diagnosis, adrenal imaging features, and concomitant diseases were analyzed. Results. The number of adrenal enlargements and proportion of incidental adrenal enlargement increased each year. Mean patient age was 50.32 years. Thirty-nine cases had unilateral enlargement on the left side and 3 on the right side; 36 had bilateral enlargement. Routine medical checkup was found to have the greatest chance (43.59%) of revealing clinical onsets leading to discovery. Biochemical and functional evaluation revealed 54 (69.23%) cases of nonfunctional lesions, 12 (15.38%) of subclinical Cushing syndrome, 6 (7.69%) of primary hyperaldosteronism, 1 (1.28%) of metastasis, and 5 (6.41%) of unknown functional status. Nodular adrenal enlargement (OR, 7.306; 95% CI, 1.727–28.667; P = 0.006) was a risk factor for functional lesions. Age and lesion location were not significant factors. Conclusion. Incidental adrenal enlargement is a frequent radiographic finding and is accompanied by diverse clinical factors that require proper evaluation and management. Nodular adrenal enlargement was a risk factor.

A rapid, straightforward, and sensitive approach to quantifying enantiomeric barbiturates in serum was developed by integrating ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) with large-volume sample stacking (LVSS) in capillary electrophoresis (CE). UA-DLLME was employed for sample preparation, and on-column preconcentration by using LVSS with polarity switching was implemented to enhance sensitivity. We thoroughly investigated and optimized various parameters influencing extraction and stacking to achieve optimal detection performance with the highest enrichment efficiencies. Under optimal extraction conditions (injection of a mixed solution containing 40 μL of CHCl 3 and 200 μL of tetrahydrofuran into 1 mL of a sample solution at pH 10.0), LVSS was performed using 600 mM Tris-boric acid (pH 9.5) containing 35 mM hydroxypropyl-β-cyclodextrin and sodium taurodeoxycholate hydrate. A voltage of 20 kV was applied and a preinjection water plug was loaded at a height of 25 cm for 10 s. Subsequently, the sample solution was injected at a height of 25 cm for 480 s, after which a voltage of -20 kV was applied and the sample stacking was initiated. The stacking process was completed when 95 % of the separation current was attained. Under optimized conditions, the contraction folds of the four barbiturate analytes (R, S-Secobarbital, R, S-pentobarbital) were improved by approximately 6400-fold, achieving detection limits of 0.1 ng/mL. The limits of quantification for all analyte enantiomers were 0.5-50 ng/mL, demonstrating good linearity (r > 0.997). Migration times exhibited a relative standard deviation of less than 1.7 %, whereas peak areas for the four analytes exhibited a deviation of 8.7 %. Finally, the established method was effectively applied to the analysis of human serum samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

We developed a triple-readout probe for colorimetric, fluorescent, and fluorescence-lifetime sensing of alkaline phosphatase (ALP) through the hydrolyzed ascorbic acid phosphate (AAP)-mediated formation of silver nanoparticles (AgNPs) on Ag + -deposited MoS 2 quantum dots (QDs). Ag + ions were self-assembled on a monolayer MoS 2 QD surface through the formation of Ag-S bonds. When ALP hydrolyzed AAP in an alkaline buffer, the resultant ascorbic acid (AA) triggered the reduction of the bound Ag + ions into AgNPs on the MoS 2 QD surface. The resultant AgNPs induced an efficient fluorescence quenching of the MoS 2 QDs through simultaneous static and dynamic quenching processes, generated an intense surface plasmon resonance peak, and triggered a reduction in the fluorescence lifetime of the MoS 2 QDs. Electron microscopy and spectroscopic techniques revealed the successful fabrication of Ag + -deposited MoS 2 QDs and the ALP-mediated formation of AgNPs on the MoS 2 QD surface. The linear quantification ranges for ALP were 0.05-2.5, 0.1-4, and 1-4 units L -1 in the fluorescent, colorimetric, and fluorescence-lifetime detection modes, respectively. In addition, the proposed probe integrated with an ALP-linked sandwich immunoassay exhibited high sensitivity and selectivity for the fluorescence sensing of rabbit immunoglobulin G with a detection limit of 8 pg mL -1 and linear range of 25-1000 pg mL -1 . The sensitivity of the probe is comparable to those of previously reported immunoassays involving ultrasensitive electrochemical detection, hydrogen evolution reactions, or electron spin resonance. The probe integrated with the sandwich assay serves as a promising platform for the detection of target proteins in clinical samples., (© 2021. Springer-Verlag GmbH Germany, part of Springer Nature.)

Pesticides are a family of non-biodegradable chemical compounds which widely used in agriculture to control pests and increase yield production. However, overuse or abuse of pesticides and their metabolites may cause potential toxicity for the environment as well as human health and all other living organisms, even at deficient concentrations. Consequently, the development of sensors for monitoring these compounds is significant. Recently, nanoparticles-based sensors have been extensively employed as a potential alternative or complementary analytical tool to conventional detection methods for pesticides. Among them, gold nanoparticles (AuNPs) owing to their unique optical properties have been developed as smart sensors with high selectivity, sensitivity, simplicity, and portability. These comprehensive reviews have summarized various studies performed based on different detection strategies, i.e., colorimetric, fluorescence, surface-enhanced Raman scattering, and electrochemical, using AuNPs as sensing probes for pesticide analysis in various matrices. Additionally, the current challenges and future trends for developing novel AuNPs-based sensors for the detection of pesticides are also discussed.

A rapid, simple, and sensitive technique for the quantitative detection of fluoxetine and norfluoxetine enantiomers in biological fluids was developed based on the combination of field-amplified sample stacking (FASS)-related capillary electrophoresis (CE) with ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME). The extraction efficiency of UA-DLLME was strongly related to extraction time, salt concentration, type of extraction and dispersion solvents, and volume of extraction and dispersion solvents. The extracted fluoxetine and norfluoxetine enantiomers in a mixture of 50% methanol and 50% deionized water were efficiently stacked using FASS and then separated using cyclodextrin-modified CE. Under optimal conditions of FASS (chiral selector, 3 mM trimethyl-β-cyclodextrin; and background electrolyte, 100 mM phosphate buffer) and UA-DLLME (extraction solvent, 200 μL of acetone; and dispersed solvent, 50 μL of C 2 H 2 Cl 4 in 1 mL of the sample solution), the obtained enrichment factors of fluoxetine and norfluoxetine enantiomers reached approximately 2000. The linear ranges for the quantification of fluoxetine and norfluoxetine enantiomers were 0.3-150 and 0.6-150 nM, respectively. The relative standard deviations in peak areas and migration time for four analytes were less than 3.3% and 6.3%, respectively. The proposed system provided limits of detection (signal-to-noise ratio of 3) for four analytes corresponding to 0.1 nM. The precision and accuracy for urine and serum samples were less than 6.8 and 8.3%, respectively. These findings suggested that the proposed system exhibited a high potential for the reliable determination of fluoxetine and norfluoxetine enantiomers in clinical samples. Graphical abstract.

In this chapter, we describe a method to identify amino acids (AA) by capillary electrophoresis in conjunction with light-emitting diode-induced fluorescence (LEDIF). First, amino acids labeled with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide are converted to highly fluorescent cyanobenz[f]isoindole (CBI) derivatives. Next, they are separated by gel electrophoresis in the presence of EOF. In the process, the CBI products were excited by a violet LED to produce green fluorescence. In addition to the optical setup of light-emitting diode-induced fluorescence, the preparation of poly(ethylene) oxide for amino acid separation is also described in this chapter.

This paper describes the synthesis of core-shell CdSe/CdS quantum dots (QDs) in aqueous solution by a simple photoassisted method. CdSe was prepared from cadmium nitrate and 1,1-dimethylselenourea precursors under illumination for up to 3 h using a pulsed Nd:YAG laser at 532 nm. The effects that the temperature and the laser irradiation process have on the synthesis of CdSe were monitored by a series of experiments using the precursors at a Cd:Se concentration ratio of 4. Upon increasing the temperature (80-140 degrees C), the size of the CdSe QDs increases and the time required for reaching a maximum photoluminescence (PL) is shortened. Although the as-prepared CdSe QDs possess greater quantum yields (up to 0.072%) compared to those obtained by microwave heating (0.016%), they still fluoresce only weakly. After passivation of CdSe (prepared at 80 degrees C) by CdS using thioacetamide as the S source (Se:S concentration ratio of 1) at 80 degrees C for 24 h, the quantum yield of the core-shell CdSe/CdS QDs at 603 nm is 2.4%. Under UV irradiation of CdSe/CdS for 24 h using a 100-W Hg-Xe lamp, the maximum quantum yield of the stable QDs is 60% at 589 nm. A small bandwidth (W1/2 < 35 nm) indicates the narrow size distribution of the as-prepared core-shell CdSe/CdS QDs. This simple photoassisted method also allows the preparation of differently sized (3.7-6.3-nm diameters) core-shell CdSe/CdS QDs that emit in a wide range (from green to red) when excited at 480 nm.