In situ self-assembled reduced graphene oxide aerogel embedded with nickel oxide nanoparticles for the high-efficiency separation of ovalbumin

A three-dimensional reduced graphene oxide aerogel with embedded nickel oxide nanoparticles was prepared by a one-step self-assembly reaction in a short time. The nanoparticles could be captured into the interior of reduced graphene oxide network duri…

Identification and determination of synthetic cannabinoids in herbal products by dry film attenuated total reflectance-infrared spectroscopy

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Victor de la Asunción-Nadal, Sergio Armenta, Salvador Garrigues, Miguel de la Guardia
A new procedure has been developed for the identification and quantitative determination of synthetic cannabinoids in illicit herbal preparations. The methodology is based on the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) measurement of sample extracts with 2-propanol drying 5µL of the extracts onto the ATR crystal. The qualitative identification was carried out on the 2-propanol extract after identification of the herbal matrix, followed by its subtraction and using a cut-off criterion of 75%. Quantitative determination was made by univariate calibration using the absorbance of the band located at 1520cm-1 of the spectrum. Four different cannabinoids, RCS-4, JWH-210, UR-144 and JWH-081 were used as test analytes and the ATR-FTIR method provided limits of quantification from 14 till 79mgL-1. Sized blank market samples were successfully identified and UR-144 quantified.

Graphical abstract


Ferrocene-graphene sheets for high-efficiency quenching of electrochemiluminescence from Au nanoparticles functionalized cadmium sulfide flower-like three dimensional assemblies and sensitive detection of prostate specific antigen

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Jiu-Jun Yang, Jun-Tao Cao, Hui Wang, Yan-Ming Liu, Shu-Wei Ren
A signal-switchable electrochemiluminescence (ECL) aptasensor was presented for sensitive prostate specific antigen (PSA) assay using ferrocene-graphene sheets (Fc-GNs) for high-efficiency quenching of ECL from Au nanoparticles functionalized cadmium sulfide flower-like three dimensional (3D) assemblies (Au-CdS flower-like 3D assemblies). Au-CdS flower-like 3D assemblies were synthesized and employed as luminophore, exhibiting strong and stable ECL intensity, and followed by assembling captured DNA (cDNA) and hybridizing it with half of base sequence of PSA aptamer on the Au-CdS flower-like 3D assemblies modified electrode. The remaining part of the non-complementary base of the aptamer could preferentially adsorb GN with the signal switched “off” state. While in the presence of the PSA, the binding of PSA with aptamer caused desorption of aptamer from the surface of Fc-GNs and was then released from electrode surface, thus allowing the ECL signal enhancement. With the transformation of luminescence signal from “off” to “on”, the aptasensor displays high sensitivity for PSA detection with a linear range from 1pgmL−1 to 25ngmL−1 and a detection limit of 0.38pgmL−1S/N=3). Moreover, this developed method could be successfully applied to the determination of PSA in human serum samples with recoveries of 85.8–104.0%, suggesting great potential applications in biochemical analysis.

Graphical abstract


A quantitative approach for Cd, Cu, Fe and Mn through laser ablation imaging for evaluating the translocation and accumulation of metals in sunflower seeds

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Gustavo de S. Pessôa, Cícero A. Lopes Júnior, Katherine C. Madrid, Marco A.Z. Arruda
The uptake and accumulation of Cd in sunflower seeds represents an important pathway for imputing potentially toxic metals into human and animal food. In this way, bioimaging of Cd and micronutrients (Cu, Fe and Mn) in the seeds of sunflower grown in soil contaminated with Cd are performed. For this task, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used in quantitative approach, considering four groups: precursor, control, Cd-low (50mg) and Cd-high (700mg). For attaining our proposals, ICP-MS (nebulizer and auxiliary flow rates and radiofrequency power) and LA (laser intensity, frequency and spot size) parameters were optimized, and the analytical signal improved to 197%, 217%, 232%, and 283%, for 57Fe, 112Cd, 55Mn and 63Cu, respectively. The accuracy of proposed method using LA-ICP-MS is evaluated comparing the CRM results (Tomato leaves, NIST SRM 1573a). No difference is found at 95% confidence level. Regarding Cd accumulation in sunflower seeds, the results indicated that cadmium is translocated to seeds, and the cotyledons showed the highest concentration (Cd-high group), ranging from 10 to 20µgg−1. Considering both total concentration and the distribution in the seeds, Cd uptake is responsible to the homeostasis misbalance of micronutrients, which play an essential role in the sunflower metabolism. Such results highlight the importance of bioimaging evaluation, in the translocation and accumulation of metals, contributing to expand the information available of this culture.

Graphical abstract


Development, validation and comparison of near infrared and Raman spectroscopic methods for fast characterization of tablets with amlodipine and valsartan

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Tibor Casian, Andra Reznek, Andreea Loredana Vonica-Gligor, Jeroen Van Renterghem, Thomas De Beer, Ioan Tomuță
The objective of this study was to develop, validate and compare NIR and Raman spectroscopic methods for fast characterization in terms of API content and tensile strength of fixed-dose combination tablets containing amlodipine and valsartan.For the APIs assay NIR-transmittance and Raman-reflectance methods were considered, whereas for the tensile strength assay Raman spectra were recorded in reflectance configuration and NIR spectra were recorded in both reflectance and transmittance. Multivariate calibration models (PLS) were built by applying different pre-processing methods (SNV, MSC, SD+SNV) on certain spectral regions. Correlating pre-processed spectral data with tablet properties resulted in highly predictive models except in the case of NIR-transmittance spectra for tensile strength estimation. The best models selected by cross-validation were further validated on independent samples in terms of linearity, trueness, accuracy and precision. Using Bland and Altman analysis the analytical performance of the NIR and Raman methods were compared, demonstrating their similarity considering the investigated applications. The two spectroscopic methods can be used in association to confirm each others results for at-line characterization of the pharmaceutical product.

Graphical abstract


Uptake of silver nanoparticles by DHA-treated cancer cells examined by surface enhanced Raman spectroscopy in a microfluidic chip

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC00053G, PaperZhiming Zhai, Fengqiu Zhang, Xiang-Yu Chen, Jie Zhong, Gang Liu, Yang-Chao Tian, Qing HuangThis paper reports synthesis and application of biocompatible and sensitive SERS nanoparticles f…

A Microfluidic Perfusion Approach for On-Chip Characterization of the Transport Properties of Human Oocytes

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C6LC01532H, PaperGang Zhao, Zhiguo Zhang, Yuntian Zhang, Zhongrong Chen, Dan Niu, Yunxia Cao, Xiaoming HeAccurate characterization of the cell membrane transport properties of human oocytes is of great si…

Atomic Force Microscopy Thermally-Assisted Microsampling with Atmospheric Pressure Temperature Ramped Thermal Desorption/Ionization-Mass Spectrometry Analysis

Analytical ChemistryDOI: 10.1021/acs.analchem.6b04733

Flow Cytometric Single-Cell Analysis for Quantitative in Vivo Detection of Protein–Protein Interactions via Relative Reporter Protein Expression Measurement

Analytical ChemistryDOI: 10.1021/acs.analchem.6b03603

Collisions of Ir Oxide Nanoparticles with Carbon Nanopipettes: Experiments with One Nanoparticle

Analytical ChemistryDOI: 10.1021/acs.analchem.6b04140

UHPLC–MS/MS quantification combined with chemometrics for the comparative analysis of different batches of raw and wine-processed Dipsacus asper

A rapid and sensitive ultra high performance liquid chromatography with tandem mass spectrometry approach was established for the simultaneous determination of 4-caffeoylquinic acid, loganic acid, chlorogenic acid, loganin, 3,5-dicaffeoylquinic acid, …

Aminosilanized magnetic carbon microspheres for the magnetic solid-phase extraction of bisphenol A, bisphenol AF. and tetrabromobisphenol A from environmental water samples

Aminosilanized magnetic carbon microspheres as a novel adsorbent were designed and fabricated. And the adsorbent was used for the magnetic solid-phase extraction of bisphenols at trace levels from environmental water samples before liquid chromatograp…

Preparation of monolithic cation-exchange material with hydrophilic external layers by two-step reversible addition-fragmentation chain transfer polymerization

In recent years, the efficient analysis of biological samples has become more important due to the advances of life science and pharmaceutical research and practice. Because biological sample pretreatment is the bottleneck for fast process, material d…

Monitoring of cefepime in human serum and plasma by micellar electrokinetic capillary chromatography: Improvement of sample preparation and validation by liquid chromatography coupled to mass spectrometry

Cefepime monitoring in deproteinized human serum and plasma by micellar electrokinetic capillary chromatography and liquid chromatography coupled to mass spectrometry in presence of other drugs is reported. For micellar electrokinetic capillary chroma…

Luminometric Label Array for Counting and Differentiation of Bacteria

Analytical ChemistryDOI: 10.1021/acs.analchem.6b05142

Indirect ultraviolet detection of alkaline earth metal ions using an imidazolium ionic liquid as an ultraviolet absorption reagent in ion chromatography

A convenient and versatile method was developed for the separation and detection of alkaline earth metal ions by ion chromatography with indirect ultraviolet detection. The chromatographic separation of Mg2+, Ca2+ and Sr2+ was performed on a carboxyli…

Extraction and separation of lactate dehydrogenase inhibitors from Poria cocos (Schw.) Wolf based on a hyphenated technique and in vitro methods

Stroke is one of the most common diseases worldwide. Lactate dehydrogenase inhibitors are widely used in the treatment of ischemic stroke, with natural products considered a promising source of lactate dehydrogenase inhibitors. In this study, ultrafil…

Identification of four cornua by ultra-performance liquid chromatography with time-of-flight mass spectrometry coupled with principal component analysis

An ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry method coupled with principal component analysis was developed and applied to the identification of Cornu Antelopis, Cornu Bubali, Cornu Naemorhedi, and C…

Development of microextraction techniques in combination with GC–MS/MS for the determination of mycotoxins and metabolites in human urine

Simple and highly efficient sample preparation procedures, namely, dispersive liquid–liquid microextraction and salting-out liquid–liquid extraction for the analysis of ten Fusarium mycotoxins and metabolites in human urine were compared. Various …

Fast and simultaneous determination of 12 polyphenols in apple peel and pulp by using chemometrics-assisted high-performance liquid chromatography with diode array detection

In this work, a smart chemometrics-enhanced strategy, high-performance liquid chromatography and diode array detection coupled with second-order calibration method based on alternating trilinear decomposition algorithm was proposed to simultaneously q…