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1.
Farré M Brix R Kuster M Rubio F Goda Y López de Alda MJ Barceló D 《Analytical and bioanalytical chemistry》2006,385(6):1001-1011
In this work four different commercially available enzyme-linked immunosorbent assays (ELISA) (from Japan EnviroChemicals,
Ltd., Tokyo, Japan) were evaluated in terms of performance for the rapid screening of estrogens in different water matrices,
including natural and spiked samples from urban wastewater, river water and ground water. All four test kits are based on
monoclonal antibodies. The compounds detected by these immunoassays are (1) 17-β-estradiol, (2) estrone, (3) 17-α-ethynyl
estradiol and (4) estrogens in general, with high recognition properties for 17-β-estradiol, estrone and estriol. Standards
were prepared in water containing 10% (v/v) methanol. The IC
50 (corresponding to the 50% of the effective concentration) values, the dynamic ranges, and the limits of detection of the
ELISA kits were 0.060–0.304 μg/L, 0.05–5 μg/L and 0.05 μg/L, respectively. All samples were extracted by solid-phase extraction
(SPE) beforehand, and the evaluation was carried out by comparing the results obtained by ELISA with those obtained by HPLC–MS/MS
using a triple quadrupole (QqQ) instrument. In addition, two different solid-phase extraction procedures were carried out
and compared. Except for moderate overestimation in the results observed with the ELISA kits in the analysis of complex wastewater
samples, the results obtained using all of the tested techniques were generally in very good agreement.
相似文献
2.
Zhixiang Xu Shuang Chen Wei Huang Guozhen Fang Hua Pingzhu Shuo Wang 《Analytical and bioanalytical chemistry》2009,393(4):1273-1279
Estrone is one of the important potential endocrine-disrupting compounds, and the sensitive and reliable analytical methods
for the determination of estrone are required for the assurance of human health. In this paper, using estrone as template
molecule, 3-aminopropyltriethoxysilane as function monomer, and tetraethoxysilicane as cross-linker, a highly selective molecularly
imprinted microsphere was synthesized by surface molecular imprinting technique combined with a sol–gel process. The imprinted
material was characterized by the Fourier transform infrared and static adsorption experiments, and the results showed that
it exhibited good recognition and selective ability for estrone. A novel method for separation and determination of trace
estrone in environmental sample was developed using on-line molecularly imprinted solid-phase extraction coupled to high-performance
liquid chromatography. With a sample loading flow rate of 2.6 mL min−1 for a 9.6-min extraction, the enrichment factor obtained by the slopes of the linear portion in comparison with the direct
injection of 10 μL standard sample solution was 1,045. The detection limit (S/N = 3) was 5.7 ng L−1, and the relative standard deviations for nine replicate extractions of 5.0 μg L−1 estrone was less than 10.0%. This method was evaluated for quantitative determination of estrone in well and lake water samples
spiked at two levels (0.5 and 1.0 μg L−1) with recoveries ranging from 86% to 95%.
相似文献
3.
Application of a new anti-zearalenone monoclonal antibody in different immunoassay formats 总被引:1,自引:0,他引:1
Natalia A. Burmistrova Irina Yu. Goryacheva Evgenia Yu. Basova Ann-Sophie Franki Dirk Elewaut Katrien Van Beneden Dieter Deforce Carlos Van Peteghem Sarah De Saeger 《Analytical and bioanalytical chemistry》2009,395(5):1301-1307
Monoclonal antibodies against zearalenone (ZEA) were raised in mice according to the hybridoma technology and applied in different
immunochemical techniques. More specifically, three formats based on the competitive direct enzyme immunoassay principle were
developed: an enzyme-linked immunosorbent assay (ELISA), a flow-through gel-based immunoassay column and a flow-through membrane-based
immunoassay. In ELISA, the 50% inhibitory concentration (IC50) was 0.8 ng/mL, and the limit of detection for ZEA standard
solutions was 0.1 ng/mL. The antibodies showed a high ZEA (100%) and α-zearalenol (α-ZOL) (69%) recognition, while cross-reactivities
with α-zearalanol, zearalanone, β-zearalenol and β- zearalanol were 42%, 22%, <1% and <1%, respectively. For standard solutions,
a cut-off level at 10 ng/mL could be established for the gel- and membrane-based enzyme immunoassays. Assay time of both non-instrumental
tests was 25 min for 10 samples. By including a simple sample extraction procedure, the methods were applied to wheat with
IC50s in ELISA of 80 and 120 μg/kg (dilution up to 5% and 15% (v/v) of wheat matrix, respectively). The cut-off level of the gel- and membrane-based immunoassays was established at 100 μg/kg.
Potentials and limitations of the developed methods were compared. The possible application for multi-mycotoxin analysis of
the ELISA method based on a single monoclonal antibody was investigated. Therefore, principal component analysis and partial
least squares regression data modelling were used to separate the immunoassay responses of two cross-reactants (ZEA and α-ZOL).
相似文献
4.
Patricia W. Stege Lorena L. Sombra Germán A. Messina Luis D. Martinez María F. Silva 《Analytical and bioanalytical chemistry》2009,394(2):567-573
Many aromatic compounds can be found in the environment as a result of anthropogenic activities and some of them are highly
toxic. The need to determine low concentrations of pollutants requires analytical methods with high sensitivity, selectivity,
and resolution for application to soil, sediment, water, and other environmental samples. Complex sample preparation involving
analyte isolation and enrichment is generally necessary before the final analysis. The present paper outlines a novel, simple,
low-cost, and environmentally friendly method for the simultaneous determination of p-nitrophenol (PNP), p-aminophenol (PAP), and hydroquinone (HQ) by micellar electrokinetic capillary chromatography after preconcentration by cloud
point extraction. Enrichment factors of 180 to 200 were achieved. The limits of detection of the analytes for the preconcentration
of 50-ml sample volume were 0.10 μg L−1 for PNP, 0.20 μg L−1 for PAP, and 0.16 μg L−1 for HQ. The optimized procedure was applied to the determination of phenolic pollutants in natural waters from San Luis,
Argentina.
Figure Schematic representation of the cloud point extraction process. 相似文献
5.
van Pinxteren MS Montero L Jäsch S Paschke H Popp P 《Analytical and bioanalytical chemistry》2009,393(2):767-775
A new approach for headspace sorptive extraction is presented and demonstrated for the determination of 12 chlorobenzenes
in water samples. It consists of a silicone tube (15-mm length) arranged around a stainless steel rod. This device is fixed
on a septum cap and exposed to the headspace of 50 mL of a salt-saturated water sample. After extraction (60-min optimized
extraction time), thermodesorption is carried out by direct insertion of the silicone tube into the thermodesorption-gas chromatography-mass
spectrometry system. Desorption of the analytes is performed at 250 °C for 5 min with a gas flow of 50 mL/min. Repeatability
(relative standard deviation 5–10%), extraction yields (9–46%), enrichment factors (129–657), and detection limits (0.002–0.012 μg/L)
were determined and four real water samples were analyzed with the headspace tube extraction. The results were verified by
standard addition. A comparison of headspace tube extraction with other headspace enrichment techniques underlined the high
extraction capacity of the proposed method. A big advantage of tube extraction is the low cost of the silicone material. The
tubes can be discarded after single use, avoiding carryover problems and cross-contamination.
Figure Scheme of the HS-tube extraction and thermodesorption system 相似文献
6.
Nan Li Hui Tang Hongwei Gai Xiuling Dong Qi Wang Edward S. Yeung 《Analytical and bioanalytical chemistry》2009,394(7):1879-1885
Determination of protein surface excess is an important way of evaluating the properties of biomaterials and the characteristics
of biosensors. A single-molecule counting method is presented that uses a standard fluorescence microscope to measure coverage
of a liquid/solid interface by adsorbed proteins. The extremely low surface excess of lysozyme and bovine serum albumin (BSA),
in a bulk concentration range from 0.3 nmol L−1 (0.02 μg mL−1) to 3 nmol L−1 (0.2 μg mL−1), were measured by recording the counts of spatially isolated single molecules on either hydrophilic (glass) or hydrophobic
(polydimethylsiloxane, PDMS) surfaces at different pH. The differences observed in amounts of adsorbed proteins under different
experimental conditions can be qualitatively explained by the combined interactions of electrostatic and hydrophobic forces.
This, in turn, implies that single-molecule counting is an effective way of measuring surface coverage at a liquid/solid interface.
Figure Adsorption fraction of proteins on different surfaces changed with pH. 相似文献
7.
Analysis and occurrence of seven artificial sweeteners in German waste water and surface water and in soil aquifer treatment (SAT) 总被引:3,自引:0,他引:3
Marco Scheurer Heinz-J. Brauch Frank T. Lange 《Analytical and bioanalytical chemistry》2009,394(6):1585-1594
A method for the simultaneous determination of seven commonly used artificial sweeteners in water is presented. The analytes
were extracted by solid phase extraction using Bakerbond SDB 1 cartridges at pH 3 and analyzed by liquid chromatography electrospray
ionization tandem mass spectrometry in negative ionization mode. Ionization was enhanced by post-column addition of the alkaline
modifier Tris(hydroxymethyl)amino methane. Except for aspartame and neohesperidin dihydrochalcone, recoveries were higher
than 75% in potable water with comparable results for surface water. Matrix effects due to reduced extraction yields in undiluted
waste water were negligible for aspartame and neotame but considerable for the other compounds. The widespread distribution
of acesulfame, saccharin, cyclamate, and sucralose in the aquatic environment could be proven. Concentrations in two influents
of German sewage treatment plants (STPs) were up to 190 μg/L for cyclamate, about 40 μg/L for acesulfame and saccharin, and
less than 1 μg/L for sucralose. Removal in the STPs was limited for acesulfame and sucralose and >94% for saccharin and cyclamate.
The persistence of some artificial sweeteners during soil aquifer treatment was demonstrated and confirmed their environmental
relevance. The use of sucralose and acesulfame as tracers for anthropogenic contamination is conceivable. In German surface
waters, acesulfame was the predominant artificial sweetener with concentrations exceeding 2 μg/L. Other sweeteners were detected
up to several hundred nanograms per liter in the order saccharin ≈ cyclamate > sucralose.
Figure Some artificial sweeteners are excreted unchanged and in particular acesulfame is a perfect tracer for municipal waste water
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
Stankov-Jovanović VP Nikolić-Mandić SD Mandić LM Mitić VD 《Analytical and bioanalytical chemistry》2006,385(8):1462-1469
Pancuronium bromide (PCBr) inhibition effect on enzyme cholinesterase from pooled human serum (Che, EC 3.1.1.8 acylcholine
acylhydrolase) was used for development of a spectrophotometric kinetic method for PCBr determination in human serum and urine.
Optimal conditions for the basic and inhibitor reactions were established: pH=7.7 and substrate concentration c(benzoylcholine
chloride)=1.33 mmol/L. Kinetic parameters were also determined: Michaelis-Menten’s constant KM=0.40 mmol/L, maximal reaction rate Vmax=52.2 μmol/L min, inhibition constant Ki=0,56 μmol/L and IC50=1.31 μmol/L. Linear dependence between the reaction rate and inhibitor concentration exists in PCBr concentration range 8.20–68.25 nmol/L,
which corresponds to the real sample concentrations from 0.328 to 2.730 μmol/L. The method detection and quantification limits
were 2.01 nmol/L and 6.67 nmol/L, respectively. Precision of the method was tested for three pancuronium concentrations (10.70,
29.35 and 51.25 nmol/L). Relative standard deviation (RSD) was in the range 0.15–7.45%. Accuracy was examined by standard
addition method. Influence of the substances usually present in serum and urine on the reaction rate was tested. The developed
method was applied for PCBr content determination in serum model samples, urine model samples and in urine taken during surgery.
The method has good sensitivity, accuracy, precision and it is suitable for clinical practice.
相似文献
9.
A sensitive and robust analytical method for the quantification of glyphosate, aminomethylphosphonic acid (AMPA) and glufosinate
in natural water has been developed on the basis of a derivatization with 9-fluorenylmethylchloroformate (FMOC-Cl), solid-phase
extraction (SPE) and liquid chromatography followed by electrospray tandem mass spectrometry (LC-ESI-MS/MS). In order to maximize
sensitivity, the derivatization was optimized regarding organic solvent content, amount of FMOC-Cl and reaction time. At an
acetonitrile content of 10% a derivatization yield of 100% was reached within two hours in groundwater and surface water samples.
After a twofold dilution the low acetonitrile content allowed solid-phase extraction of a sample of originally 80 mL over
200 mg Strata-X cartridges. In order to decrease the load of the LC column and mass spectrometer with derivatization by-products
(e.g., 9-fluorenylmethanol FMOC-OH), a rinsing step was performed for the SPE cartridge with dichloromethane. Acidification
of the sample and addition of EDTA was used to minimize complexation of the target compounds with metal ions in environmental
samples. Due to the large sample volume and the complete FMOC-OH removal, limits of quantification of 0.7 ng/L, 0.8 ng/L and
2.3 ng/L were achieved in surface water for glyphosate, AMPA and glufosinate, respectively. The limits of detection were as
low as 0.2 ng/L, 0.2 ng/L and 0.6 ng/L for glyphosate, AMPA and glufosinate, respectively. Surface water and ground water
samples spiked at 2 ng/L showed recoveries of 91–107%.
Figure LC-MS/MS chromatogram of a water sample from a remote alpine region spiked at 1 ng/L 相似文献
10.
Goryacheva IY Basova EY Van Peteghem C Eremin SA Pussemier L Motte JC De Saeger S 《Analytical and bioanalytical chemistry》2008,390(2):723-727
A rapid easy-to-use immunoassay was optimised for the non-instrumental detection of ochratoxin A (OTA) in beer. The analytical
method involves preconcentration on the immunoaffinity layer inside a column followed by direct competitive ELISA detection
in the same layer. The visual cut-off value, i.e. the lowest OTA concentration resulting in no colour development, was 0.2 μg
L-1. Assay validation was performed using samples spiked with OTA. Thirty-seven naturally contaminated samples were screened
with the gel-based method developed and no false-negative results were obtained. The method described offers a simple, rapid
and cost-effective screening tool, thus contributing to better health protection of consumers.
Figure Gel-based immunoassay of spiked beer samples. 相似文献
11.
Kim E. Sapsford Jesse Francis Steven Sun Yordan Kostov Avraham Rasooly 《Analytical and bioanalytical chemistry》2009,394(2):499-505
A previously developed fluorescence sensing platform, combining spatial illumination using electroluminescence (EL) semiconductor
strips with charge coupled device (CCD)-based detection (EL-CCD), was adapted to a new 96-well chip for colorimetric immunological
assays, enhancing the capabilities of the EL-CCD platform. The modified system was demonstrated using a colorimetric-based
enzyme linked immunosorbent assay (ELISA) for detection of staphylococcal enterotoxin B (SEB). Limits of detection (LODs)
of 3.9 ng/mL (±2.4 ng/mL) SEB were determined with the ELISA chip measured using the EL-CCD platform, following a standard
4-h ELISA protocol. The LODs were comparable to those obtained using standard 96-well ELISA plates measured using a standard
laboratory 96-well plate reader. The miniature 96-well ELISA chip however required as little as 5-μL samples, representing
a tenfold reduction in sample volume compared to a standard 96-well ELISA plates. The ELISA chip also demonstrated detection
of SEB spiked into various food matrices (milk, mushrooms, and mayonnaise) using limited-to-no sample preparation, with LODs
ranging from 3.9 to 18.5 ng/mL depending on the matrix. The EL-CCD platform is versatile, capable of multi-mode detection
(e.g., fluorescent and colorimetric along with solution and solid phase assays), and could readily be applied to other field
portable or point-of-care applications.
Figure Detection of SEB using miniature ELISA chips coupled with a portable electroluminiscent-charge couple device (EL-CCD) detection
system.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
Martínez-Cabot A Varela B Lloveras M Campos R Marco MP Messeguer A 《Analytical and bioanalytical chemistry》2008,391(2):617-624
The fatty acid esters of 3-(N-phenylamino)propane-1,2-diol (PAP) are biomarkers of toxic oil batches that caused toxic oil syndrome (TOS), an intoxication
that caused over 400 deaths and affected 20,000 people in Spain in 1981. PAP esters are converted into PAP by human pancreatic
lipase. The in vivo biotransformation of PAP in two mouse strains generated potentially toxic metabolites. Here we report
an enzyme-linked immunosorbent assay (ELISA) for PAP detection incorporating antibodies generated using PAP-hapten derivatives
1 and 2. The immunizing haptens were designed to recognize the phenylamino and hydroxymethylene moieties of the PAP structure. The
antisera raised against 1-HCH showed greater affinity for free PAP, as demonstrated in competitive experiments using either 1-BSA or 2-BSA as coating antigens. The developed ELISA detects PAP at a threshold of 130 μg L−1 and can be used over a wide range of pH and ionic strength values. The assay can be applied to human urine samples, after
a simple treatment method, with good recovery according to the correlation obtained when analyzing blind spiked urine samples.
Figure Development of an ELISA for PAP in human urine 相似文献
13.
Khalid Hamad Abu-Shandi 《Analytical and bioanalytical chemistry》2009,395(2):527-532
A high-performance liquid chromatographic (HPLC) method with fluorescence detection for the quantification of vancomycin in
human plasma was developed and validated. The method includes an extraction of vancomycin by deproteinization with acetonitrile.
The analyses were carried out at 258 nm as the emission wavelength while exciting at 225 nm on a reversed-phase column (30 cm × 4 mm
i.d. × 10 μm Waters Associates μBondapak C18) using a mobile phase composed of methanol and phosphate buffer at pH 6.3. Vancomycin
was quantitatively recovered from human plasma samples (>96%) with high values of precision. The separation was completed
within 27 min. The calibration curve was linear over the range from 5 to 1,000 ng/mL with the detection and quantification
limits of 2 ng/mL and 5 ng/mL, respectively. This method is suitable for the routine assay of plasma samples.
Figure The effect of the deproteinization solvent on the signal of the interference peak at retention time of 15.0 min. The peak
which interferes with the peaks of Erythromycin and Vancomycin has been disappeared by using 2 mL acetonitrile as the deproteinization
solvent. 相似文献
14.
Zaher M Ravelet C Baussanne I Ravel A Grosset C Décout JL Peyrin E 《Analytical and bioanalytical chemistry》2009,393(2):655-660
In this paper, we describe the preparation and the evaluation of a porous graphitic carbon (PGC) column coated with a new
dinaphthyl derivative of neamine for chiral ligand-exchange (LE) chromatography. It was shown that the graphitic surface/dinaphthyl
anchor system efficiently (1.15 μmol/m2) and stably (three months of intensive use) adsorbs the neamine template onto the chromatographic support. The resulting
coated PGC stationary phase showed appreciable LE-based enantioselective properties towards several native amino acids.
Chromatographic separation of methionine enantiomers using a dinaphtyl neamine-based ligand-exchange chiral stationary phase 相似文献
15.
Development of a chemiluminescent ELISA and a colloidal gold-based LFIA for TNT detection 总被引:1,自引:0,他引:1
S. Girotti S. Eremin A. Montoya M. J. Moreno P. Caputo M. D’Elia L. Ripani F. S. Romolo E. Maiolini 《Analytical and bioanalytical chemistry》2010,396(2):687-695
To identify the explosive used in a terrorist attack, or to obtain an early sign of environmental pollution it is important
to use simple and rapid assays able to detect analytes at low levels, possibly on-site. This is particularly true for TNT
(2,4,6-trinitrotoluene), one of the most employed explosives in the 20th century and at the same time, because of its toxicity,
a well known pollutant. In this work we describe the development of an indirect competitive ELISA with chemiluminescent detection
(CL-ELISA) and of a lateral-flow immunoassay (LFIA) based on colloidal gold nanoparticle labels. A commercially available
monoclonal antibody was used and 13 specially synthesized conjugates were tested. We optimized the assay by determining the
optimal concentration of monoclonal antibody and conjugates and the influence of various non-specific factors such as: tolerance
to organic solvents at different concentrations, the washing and competitive step time, and the cross-reactivity with related
compounds. The sensitivity and reproducibility of the CL-ELISA were good (LOD and IC50 values in the ng mL−1 range, and CV value about 7%). It has been applied to real samples of various materials involved in a controlled explosion
of an “improvised explosive device”. Three extraction procedures were tested on these samples, all employing methanol as the
solvent. The lateral flow immunoassay (LFIA), developed by using the same immunoreagents, reached a detection limit of 1 μg mL−1 when tested on the same samples analysed by CL-ELISA.
相似文献
16.
Llamas NM Stewart L Fodey T Higgins HC Velasco ML Botana LM Elliott CT 《Analytical and bioanalytical chemistry》2007,389(2):581-587
The mouse bioassay is the methodology that is most widely used to detect okadaic acid (OA) in shellfish samples. This is one
of the best-known toxins, and it belongs to the family of marine biotoxins referred to as the diarrhetic shellfish poisons
(DSP). Due to animal welfare concerns, alternative methods of toxin detection are being sought. A rapid and specific biosensor
immunoassay method was developed and validated for the detection of OA. An optical sensor instrument based on the surface
plasmon resonance (SPR) phenomenon was utilised. A polyclonal antibody to OA was raised against OA–bovine thyroglobulin conjugate
and OA–N-hydroxy succinimide ester was immobilised onto an amine sensor chip surface. The assay parameters selected for the analysis
of the samples were: antibody dilution, 1/750; ratio of antibody to standard, 1:1; volume of sample injected, 25 μl min−1; flow rate, 25 μl min−1. An assay action limit of 126 ng g−1 was established by analysing of 20 shellfish samples spiked with OA at the critical concentration of 160 ng g−1, which is the action limit established by the European Union (EU). At this concentration of OA, the assay delivered coefficient
of variations (CVs) of <10%. The chip surface developed was shown to be highly stable, allowing more than 50 analyses per
channel. When the concentrations of OA determined with the biosensor method were compared with the values obtained by LC–MS
in contaminated shellfish samples, the correlation between the two analytical methods was found to be highly satisfactory
(r
2 = 0.991).
Figure Biacore 相似文献
17.
In-torch LA–ICP–MS was implemented into an in-house-built ICP–TOFMS system. The fast data acquisition capabilities of the
new configuration allowed simultaneous multi-element measurement and readout of in-torch LA–ICP–MS signals with 30 μs time
resolution. The measurements confirmed previously observed fine structures of in-torch generated signals and provided new
insights in the dynamic processes in the plasma on a microsecond time scale. The new setup is described in detail and first
figures of merit are given.
Figure Time dependent multi element signal after laser ablation in the torch of an ICP-TOFMS instrument 相似文献
18.
Simmel F Soukup J Zoerner A Radke J Kloft C 《Analytical and bioanalytical chemistry》2008,392(3):479-488
Voriconazole is a very potent antifungal agent used to treat serious fungal infections (candidiasis); it is also the therapy
of choice for aspergillosis. After standard dosing, several factors affect exposure of voriconazole, resulting in large variability
and demanding further elucidation of drug distribution. For measurements at the site of action, microdialysis is considered
to be an outstanding minimally invasive method. For determination of voriconazole in microdialysate and human plasma a new,
efficient, reliable, and robust HPLC assay using UV detection at 254 nm has been developed and validated. After simple sample
preparation using acetonitrile for plasma and for microdialysate, 20 μL were injected and separated on an RP-18 column. The
chromatographic run time was less than 4 min. Overall, the assay showed high precision (CV 93.9 to 99.5%) and accuracy (RE
−96.7 to +107%) for both matrices. Of the 36 drug products typically co-administered with voriconazole, none except ambroxol
interfered with its peak signal, and this interference was successfully managed. In summary, the method is highly suitable
for application in (pre)clinical microdialysis studies, e.g., of critically ill patients with invasive mycoses.
Figure Microdialysis probe situated in the interstitial space fluid containing voriconazole drug molecules (magenta coloured) extracting
an important target site representative matrix (microdialysate) [Courtesy of CMA] 相似文献
19.
Ortner K Sivanandam VN Buchberger W Müller N 《Analytical and bioanalytical chemistry》2007,388(1):173-177
Enzymatically cleaved glycans from sub-milligram quantities of erythropoietin (EPO) and ovalbumin have been analyzed, without
further purification, by two-dimensional diffusion-ordered nuclear magnetic resonance spectroscopy. At NMR sample concentrations
below 50 μmol L−1 the major components of the oligosaccharide fractions could be distinguished by their anomeric proton chemical shift and
their size-dependent diffusion coefficients.
Figure
1H NMR diffusion decay curves of anomeric protons in the EPO glycan fraction 相似文献
20.
This article describes the use of microfluidic paper-based analytical devices (μPADs) to perform quantitative chemical assays
with internal standards. MicroPADs are well-suited for colorimetric biochemical assays; however, errors can be introduced
from the background color of the paper due to batch difference and age, and from color measurement devices. To reduce errors
from these sources, a series of standard analyte solutions and the sample solution are assayed on a single device with multiple
detection zones simultaneously; an analyte concentration calibration curve can thus be established from the standards. Since
the μPAD design allows the colorimetric measurements of the standards and the sample to be conducted simultaneously and under
the same condition, errors from the above sources can be minimized. The analytical approach reported in this work shows that
μPADs can perform quantitative chemical analysis at very low cost.
相似文献