共查询到20条相似文献,搜索用时 15 毫秒
1.
Leveriza F. Arenas Benilda S. Ebarvia Fortunato B. Sevilla III 《Analytical and bioanalytical chemistry》2010,397(7):3155-3158
A piezoelectric quartz crystal (PQC) sensor based on a molecularly imprinted polymer (MIP) has been developed for enantioselective
and quantitative analysis of d-(+)-methamphetamine (d(+)-MA). The sensor was produced by bulk polymerization and the resulting MIP was then coated on the
gold electrode of an AT-cut quartz crystal. Conditions such as volume of polymer coating, curing time, type of PQC, baseline
solvent, pH, and buffer type were found to affect the sensor response and were therefore optimized. The PQC-MIP gave a stable
response to different concentrations of d(+)-MA standard solutions (response time = 10 to 100 s) with good repeatability (RSD = 0.03
to 3.09%; n = 3), good reproducibility (RSD = 3.55%; n = 5), and good reversibility (RSD = 0.36%; n = 3). The linear range of the sensor covered five orders of magnitude of analyte concentration, ranging from 10−5 to 10−1 μg mL−1, and the limit of detection was calculated as 11.9 pg d(+)-MA mL−1
. The sensor had a highly enantioselective response to d(+)-MA compared with its response to l(−)-MA, racemic MA, and phentermine.
The developed sensor was validated by applying it to human urine samples from drug-free individuals spiked with standard d(+)-MA
and from a confirmed MA user. Use of the standard addition method (SAM) and samples spiked with d(+)-MA at levels ranging
from 1 × 10−3 to 1 × 10−2 μg mL−1 showed recovery was good (95.3 to 110.9%). 相似文献
2.
It was found that tripropylamine (TPA) could be used as a coreactant to initiate the electrochemiluminescence (ECL) of acridinium
NHS ester (AE NHS) labels attached to DNA. The radicals generated in the electro-oxidation process of TPA reacted with AE
NHS to form the excited N-methylacridone, giving rise to light emission. The AE/TPA ECL system was for the first time used as the detection system
for developing an ECL-based DNA sensor. In the protocol, streptavidin-modified gold nanoparticles were firstly immobilized
onto a thiol-treated gold electrode. The streptavidin could specifically interact with the biontinylated capture DNA. Afterwards,
the target DNA and the AE-labeled report DNA were conjugated onto the electrode step by step due to the hybridization reactions,
and a sandwich-type sensor was fabricated. The ECL signals of the sensor were obtained under pulse potential condition in
alkaline solution containing 50.0 mmol L−1 TPA. Under optimized experimental conditions, the linear range of the DNA sensor for the determination of the target DNA
was from 5.0 × 10−15 to 5.0 × 10−12 mol L−1. The detection limit (S/N = 3) was 3.0 × 10−15 mol L−1. Moreover, the sensor could specifically recognize the target DNA against one base-pair mismatched sequences, two base-pair
mismatched sequences, and the noncomplementary sequences. It is of great application potential in clinic analysis. 相似文献
3.
Radoi A Compagnone D Batic M Klincar J Gorton L Palleschi G 《Analytical and bioanalytical chemistry》2007,387(3):1049-1058
Bulk screen-printed electrodes (bSPEs) modified with zirconium phosphate (ZrP) and Meldola blue (MB) and by electrochemical deposition of a Reineckate film
(bMBZrPRs-SPEs) have been constructed and used as NADH sensors. Cyclic voltammetric investigation of these bulk electrochemically
modified screen-printed electrodes revealed stable catalytic activity in oxidation of the reduced form of the coenzyme nicotinamide
adenine dinucleotide (NADH). Flow-injection analysis (FIA) coupled with amperometric detection confirmed the improved stability
of the bMBZrPRs-SPEs (10−4 mol L−1 NADH, %RSD = 4.2, n = 90, pH 7.0). Other conditions, for example applied working potential (+50 mV relative to Ag|AgCl), flow rate (0.30 mL min−1) and pH-dependence (range 4.0–10.0) were evaluated and optimized. A glycerol biosensor, prepared by immobilizing glycerol
dehydrogenase (GDH) on the working electrode area of a bMBZrPRs-SPE, was also assembled. The biosensor was most stable at pH 8.5 (%RSD = 5.6, n = 70, 0.25 mmol L−1 glycerol). The detection and quantification limits were 2.8 × 10−6 and 9.4 × 10−6 mol L−1, respectively, and the linear working range was between 1.0 × 10−5 and 1.0 × 10−4 mol L−1. To assess the effect of interferences, and recovery by the probe we analyzed samples taken during fermentation of chemically
defined grape juice medium and compared the results with those obtained by HPLC. 相似文献
4.
Eduardo Marafon Lauro T. Kubota Yoshitaka Gushikem 《Journal of Solid State Electrochemistry》2009,13(3):377-383
SiO2/ZrO2/C carbon ceramic material with composition (in wt%) SiO2 = 50, ZrO2 = 20, and C = 30 was prepared by the sol–gel-processing method. A high-resolution transmission electron microscopy image
showed that ZrO2 and the graphite particles are well dispersed inside the matrix. The electrical conductivity obtained for the pressed disks
of the material was 18 S cm−1, indicating that C particles are also well interconnected inside the solid. An electrode modified with flavin adenine dinucleotide
(FAD) prepared by immersing the solid SiO2/ZrO2/C, molded as a pressed disk, inside a FAD solution (1.0 × 10−3 mol L−1) was used to investigate the electrocatalytic reduction of bromate and iodate. The reduction of both ions occurred at a peak
potential of −0.41 V vs. the saturated calomel reference electrode. The linear response range (lrr) and detection limit (dl)
were: BrO3
−, lrr = 4.98 × 10−5–1.23 × 10−3 mol L−1 and dl = 2.33 μmol L−1; IO3
−, lrr = 4.98 × 10−5 up to 2.42 × 10−3 and dl = 1.46 μmol L−1 for iodate. 相似文献
5.
This work presents a comparison of convective interaction media (CIM) and controlled pore glass (CPG) as solid supports for
immunoglobulin antibodies used in bioanalytical detection of allergens in foodstuffs. A flow-injection manifold with highly
sensitive thermal lens spectrometric detection was used for this purpose. Using beta-lactoglobulin, a milk allergen, as a
model analyte, CIM disc supports had a higher linear range (0.2–3.5 μg L−1), better reproducibility (intra-day RSD = 1%, inter-day RSD = 10%), lower consumption of reagents, and better immunocolumn
stability (1 month, over 240 injections of substrate), while providing comparable LODs (0.1 μg L−1). Application of CIM discs as solid supports in immunocolumns for allergen detection enables fast and sensitive screening
of allergens in foodstuffs with sample throughput of up to eight samples per hour. 相似文献
6.
Ying Xu Fei Wang Le Wang Fangyuan Zhao Baocheng Yang Baoxian Ye 《Journal of Solid State Electrochemistry》2012,16(4):1473-1480
A novel voltammetric sensor, based on single-walled carbon nanotubes (SWNT) dispersed in Nafion and modified glassy carbon
electrode (GCE), was fabricated and used to determine the trace amounts of dihydromyricetin (DMY). The electrochemical behavior
of DMY at this sensor was investigated in 0.1 mol L−1 sulfuric acid solutions + 0.1 mol L−1 NaCl by cyclic voltammetry and squarewave voltammetry. Compared with bare GCE, the electrode presented an excellent response
of DMY through an adsorption-controlled quasi-reversible process. Under the optimum conditions, the response peak currents
were linear relationship with the DMY concentrations in the range of 1.0 × 10−7–1.0 × 10−5 mol L−1 with a detection limit of 9 × 10−8 mol L−1. Based on this voltammetric sensor, a simple and sensitive electroanalytical method for DMY was proposed and applied to quantitative
determination of DMY in Ampelopsis grossedentata samples. In addition, the oxidation mechanism was proposed and discussed, which could be a reference for the pharmacological
action of DMY in clinical study. 相似文献
7.
Carboxyl group-functionalized single-walled carbon nanotubes (SWNTs) and 2,6-pyridinedicarboxylic acid (PDC) were electropolymerized
by cyclic voltammetry on a glassy-carbon electrode (GCE) surface to form composite films (SWNTs/PDC). Zirconia was then electrodeposited
on the SWNTs/PDC/GCE from an aqueous electrolyte containing ZrOCl2 and KCl by cycling the potential between −1.1 V and +0.7 V at a scan rate of 20 mV s−1. DNA probes with a phosphate group at the 5′ end were easily immobilized on the zirconia thin films, because of the strong
affinity between zirconia and phosphate groups. The sensors were characterized by cyclic voltammetry (CV) and electrochemical
impedance spectroscopy (EIS). EIS was used for label-free detection of the target DNA by measuring the increase of the electron
transfer resistance (R
et) of the electrode surface after the hybridization of the probe DNA with the target DNA. The PAT gene fragment and polymerase
chain reaction (PCR) amplification of the NOS gene from transgenically modified beans were satisfactorily detected by use
of this DNA electrochemical sensor. The dynamic range of detection of the sensor for the PAT gene fragment was from 1.0 × 10−11 to 1.0 × 10−6 mol L−1 and the detection limit was 1.38 × 10−12 mol L−1. 相似文献
8.
The electrooxidative behaviour and determination of quetiapine (QTP), a dibenzothiazepine derivative and antipsychotic agent,
on a glassy carbon disc electrode was investigated using cyclic (CV), linear sweep (LSV), differential pulse (DPV) and Osteryoung
square wave voltammetry (OSWV). Fully validated DP and SW voltammetric procedures are described for the determination of QTP.
QTP in pH 3.5 acetate buffer solution presents a well-defined anodic response, studied by the proposed methods. This main
response was due to the irreversible, diffusion-controlled, one-electron and one-proton oxidation of the aliphatic nitrogen
of the piperazine ring. Under optimal conditions, a detection limit of 4.0 × 10−8 mol L−1 for DPV and 1.33 × 10−7 mol L−1 for OSWV, and a linear calibration graph in the range from 4.0 × 10−6 to 2.0 × 10−4 mol L−1 were obtained for both methods. The procedure was successfully applied to the determination of the drug in tablets, human
serum and human urine with good recoveries. The detection limits were 6.20 × 10−7 mol L−1 and 5.92 × 10−7 mol L−1 in human serum and 1.44 × 10−7 mol L−1 and 1.31 × 10−6 mol L−1 in human urine, for the DPV and OSWV method, respectively. 相似文献
9.
An electrochemical study of the doxazosin oxidative process at carbon paste electrodes using different voltammetric techniques
has been carried out. The process is irreversible and controlled by adsorption, giving rise to an oxidation wave around 1.0 V
in citric acid-citrate buffer (pH 3.0). A mechanism based on the oxidation of the amine group is postulated. Two methods based
on adsorptive stripping (AdS) of doxazosin at the C8-modified carbon paste electrode (C8-MCPE), before its voltammetric determination, are studied, using differential pulse voltammetry (DPV) and square wave voltammetry
(SWV) as redissolution techniques. By means of AdS-DPV and C8-MCPE, doxazosin can be determined over the 1.0 × 10−9 to 3.0 × 10−8 mol L−1 range with a variation coefficient of 2.2% (2.0 × 10−8 mol L−1) and a limit of detection of 7.4 ×10−10 mol L−1. If AdS-SWV is used, a linear range from 1.0 × 10−9 to 4.0 × 10−8 mol L−1 is obtained, the variation coefficient being 2.8% (2.0 × 10−8 mol L−1, and the limit of detection reached 7.7 × 10−10 mol L−1. The AdS-DPV procedure was applied to the determination of doxazosin in urine and formulations.
Received March 13, 1999. Revision December 23, 1999. 相似文献
10.
Song Wei Chen Yu Xu Juan Yang Xiao-Rong Tian Dan-Bi 《Journal of Solid State Electrochemistry》2010,14(10):1909-1914
Molecularly imprinted polymers (MIPs) have been applied as molecular recognition elements to chemical sensors. In this paper,
we combined the use of MIPs and electropolymerization to produce a sensor which was capable of detecting dopamine (DA). The
MIP electrode was obtained by electrocopolymerization of o-phenylenediamine and resorcinol in the presence of the template molecular DA. The MIP electrode exhibited a much higher current
response compared with the non-imprinted electrode. The response of the imprinted sensor to DA was linearly proportional to
its concentration over the range 5.0 × 10−7-4.0 × 10−5 M. The detection limit of DA is 0.13 μM (S/N = 3). Moreover, the proposed method could discriminate between DA and its analogs, such as ascorbic acid and uric acid. This
method was successfully applied to the determination of DA in dopamine hydrochloride injection and healthy human blood serum.
These results revealed that such a sensor fulfilled the selectivity, sensitivity, sped, and simplicity requirements for DA
detection and provided possibilities of clinical application in physiological fields. 相似文献
11.
Jun Yue Bai Liang Wang Hong Jing Wang Peng Fei Huang Yu Qing Zhao Sheng Di Fan 《Mikrochimica acta》2006,156(3-4):321-326
The electrochemical behavior of epinephrine (EP) at a mercaptoacetic acid (MAA) self-assembled monolayer modified gold electrode
was studied. The MAA/Au electrode is demonstrated to promote the electrochemical response of epinephrine by cyclic voltammetry.
The possible reaction mechanism is also discussed. The diffusion coefficient D of EP is 6.85 × 10−6 cm2 s−1. In 0.1 mol L−1 phosphate buffer (pH 7.20), a sensitive oxidation peak was observed at 0.177 V, and the peak current is proportional to the
concentration of EP in the range of 1.0 × 10−5–2.0 × 10−4 mol L−1 and 1.0 × 10−7–1.0 × 10−6 mol L−1. The detection limit is 5 × 10−8 mol L−1. The modified electrode is highly stable and can be applied to the determination of EP in practical injection samples. The
method is simple, quick, sensitive and accurate. 相似文献
12.
Xiaoying Liu Yonghong Li Xinsheng Liu Xiandong Zeng Bo Kong Shenglian Luo Wanzhi Wei 《Journal of Solid State Electrochemistry》2012,16(3):883-889
A simple sensor based on bare carbon ionic liquid electrode was fabricated for simultaneous determination of dihydroxybenzene
isomers in 0.1 mol L−1 phosphate buffer solution (pH 6.0). The oxidation peak potential of hydroquinone was about 0.136 V, catechol was about 0.240 V,
and resorcinol 0.632 V by differential pulse voltammetric measurements, which indicated that the dihydroxybenzene isomers
could be separated absolutely. The sensor showed wide linear behaviors in the range of 5.0 × 10−7–2.0 × 10−4 mol L−1 for hydroquinone and catechol, 3.5 × 10−6–1.535 × 10−4 mol L−1 for resorcinol, respectively. And the detection limits of the three dihydroxybenzene isomers were 5.0 × 10−8, 2.0 × 10−7, 5.0 × 10−7 mol L−1, respectively (S/N = 3). The proposed method could be applied to the determination of dihydroxybenzene isomers in artificial wastewater and
the recovery was from 93.9% to 104.6%. 相似文献
13.
Huang KJ Zhang M Xie WZ Zhang HS Feng YQ Wang H 《Analytical and bioanalytical chemistry》2007,388(4):939-946
A simple, sensitive, selective, and low-cost method is proposed for rapidly determining nitric oxide (NO) in some rat tissues.
Polymer monolith microextraction (PMME) using a poly(methacrylic acid–ethylene glycol dimethacrylate) (MAA-EGDMA) monolithic
column was combined with derivatization of NO using 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza-s-indacene (TMDABODIPY), and this was used to analyze the derivatives of NO by high-performance liquid chromatography (HPLC)
with fluorescence detection at λ
ex/λ
em = 498/507 nm. The baseline separation of TMDABODIPY and its NO derivative is performed under simple conditions in which a
C18 column is used and eluted with 50 mmol L−1 ethanolamine and methanol. The conditions for the extraction of NO derivatives were optimized. The limit of detection of
NO was 2 × 10−12 mol L−1 (S/N = 3). The linearity range of the method was 9 × 10−11−4.5 × 10−8 mol L−1. The interday and intraday relative standard deviations were less than 5%. The proposed method was successfully applied to
the determination of NO levels in some rat tissue samples including heart, kidney, and liver with recoveries varying from
87.1 to 95.2%. 相似文献
14.
A novel fluorescence quenching method for the determination of cationic surfactants (CS), specifically cetyltrimethylammonium
bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), and cetylpyridinium chloride (CPC), has been developed using water-soluble
luminescent CdTe quantum dots (QDs) modified with thioglycolic acid (TGA). The possible interference from heavy and transition
metals (HTM) has been efficiently eliminated through simple sample treatment with mercapto cotton made in-house. Under optimum
conditions, the extent of fluorescence quenching of CdTe QDs is linearly proportional to the concentration of CS from 2.0 × 10−7 to 7.0 × 10−6 mol L−1 with a detection limit of 5.0 × 10−8 mol L−1. The relative standard deviation for 1.0 × 10−6 mol L−1 CTAB is 2.5% (n = 6). The proposed method exhibits high sensitivity and selectivity and furthermore avoided the use of toxic organic solvents
and tedious solvent extraction procedures. It has been applied to the determination of trace CS in natural river water and
commodity samples with satisfactory results.
Potential interference from heavy and transition metals is eliminated during photoluminescence detection of CS through simple
sample pre-treatment with mercapto cotton 相似文献
15.
A poly(caffeic acid) thin film was deposited on the surface of a glassy carbon electrode by potentiostatic technique in an
aqueous solution containing caffeic acid. The poly(caffeic acid)-modified electrode was used for the determination of ascorbic
acid (AA), dopamine (DA), and their mixture by cyclic voltammetry. This modified electrode exhibited a potent and persistent
electron-mediating behavior followed by well-separated oxidation peaks toward AA and DA at a scan rate of 10 mV s−1 with a potential difference of 135 mV, which was large enough to determine AA and DA individually and simultaneously. The
catalytic peak current obtained was linearly dependent on the AA and DA concentrations in the range of 2.0 × 10−5−1.2 × 10−3 and 1.0 × 10−6−4.0 × 10−5 mol L−1 in 0.15 mol L−1 phosphate buffer (pH 6.64). The detection limits for AA and DA were 9.0 × 10−6 and 4.0 × 10−7 mol L−1, respectively. The modified electrode shows good sensitivity, selectivity, and stability and has been applied to the determination
of DA and AA in real samples with satisfactory results. 相似文献
16.
A sensitive adsorptive anodic stripping procedure for the determination of trace zirconium at a carbon paste electrode (CPE)
has been developed. The method is based on adsorptive accumulation of the Zr(IV)-alizarin red S(ARS) complex onto the surface
of the CPE, followed by oxidation of adsorbed species. The optimal experimental conditions include the use of 0.10 mol · L−1 ammonium acetate buffer (pH 4.3), ARS, an accumulation potential of 0.20 V (versus SCE), an accumulation time of 2 min, a
scan rate of 200 mV · s−1 and a second-order derivative linear scan mode. The oxidation peak for the complex appears at 0.69 V. The peak current is
proportional to the concentration of Zr(IV) over the range of 1.0 × 10−9–2.0 × 10−7 mol · L−1, and the detection limit is 3 × 10−10 mol · L−1 for a 2 min adsorption time. The relative standard deviations (n = 8) for 5.0 × 10−8 and 5.0 × 10−9 mol · L−1 Zr(IV) are 3.3 and 4.8%, respectively. The proposed method was applied to the determination of zirconium in ore samples with
satisfactory results. 相似文献
17.
Grabarczyk M 《Analytical and bioanalytical chemistry》2008,390(3):979-986
A simple and fast catalytic adsorptive stripping voltammetric procedure for trace determination of Cr(VI) in natural samples
containing high concentrations of humic substances has been developed. The procedure for chromium determination in the presence
of DTPA and nitrates was employed as the initial method. In order to enhance the selectivity vs. Cr(III) the measurements
were performed at 40°C. Interference from dissolved organic matter such as humic and fulvic acids was drastically decreased
by adding Amberlite XAD-7 resin to the voltammetric cell before the deaeration step. The whole procedure was applied to a
single cell, which allowed monitoring of the voltammetric scan. Optimum conditions for removing humic and fulvic acids due
to their adsorption on XAD-7 resin were evaluated. The use of XAD-7 resin also minimize interferences from various cationic,
anionic, and nonionic surfactants. The calibration graph for Cr(VI) for an accumulation time of 30 s was linear in the range
5 × 10−10 to 5 × 10−8 mol L−1. The relative standard deviation for determination of Cr(VI) at a concentration of 1 × 10−8 mol L−1 was 3.5% (n = 5). The detection limit estimated from 3 times the standard deviation for low Cr(VI) concentrations and an accumulation
time of 30 s was about 1.3 × 10−10 mol L−1. The proposed method was successfully applied to Cr(VI) determination at trace levels in soil samples. 相似文献
18.
We have developed a circular-dichroism thermal lens microscope for UV wavelengths (UV-CD-TLM), for the first time, to realize
sensitive chiral analysis on a microchip. Quasi-continuous-wave phase modulation of a pulsed UV laser was used to generate
left-circularly polarized light and right-circularly polarized light and to detect the generated TL signal amplitude and phase
with a lock-in amplifier. The amplitude and phase were used to determine the concentration and chirality, respectively, of
a sample. The basic principle of UV-CD-TLM for chiral analysis on a microchip was verified by measuring aqueous solutions
of optically active camphorsulfonic acids (CSA). Lower limits of detection (LOD) were calculated at S/N = 2 and were 8.7 × 10−4 mol L−1 (ΔA = 5.2 × 10−6 Abs.) for (+)-CSA and 8.4 × 10−4 mol L−1 (ΔA = 5.0 × 10−6 Abs.) for (−)-CSA. In terms of number of molecules, LODs for UV-CD-TLM were calculated to be 8.7 fmol and 8.4 fmol, respectively.
This is at least three orders of magnitude lower than previously obtained. The applicability of UV-CD-TLM for chiral analysis
on a microchip was verified.
Figure Sensitive chiral analysis by thermal lens microscope (TLM) 相似文献
19.
Tripodal chelating ligand-based sensor for selective determination of Zn(II) in biological and environmental samples 总被引:1,自引:0,他引:1
Potassium hydrotris(N-tert-butyl-2-thioimidazolyl)borate [KTtt-Bu] and potassium hydrotris(3-tert-butyl-5-isopropyl-l-pyrazolyl)borate [KTpt-Bu,i-Pr] have been synthesized and evaluated as ionophores for preparation of a poly(vinyl chloride) (PVC) membrane sensor for Zn(II)
ions. The effect of different plasticizers, viz. benzyl acetate (BA), dioctyl phthalate (DOP), dibutyl phthalate (DBP), tributyl
phosphate (TBP), and o-nitrophenyl octyl ether (o-NPOE), and the anion excluders sodium tetraphenylborate (NaTPB), potassium tetrakis(p-chlorophenyl)borate (KTpClPB), and oleic acid (OA) were studied to improve the performance of the membrane sensor. The best
performance was obtained from a sensor with a of [KTtt-Bu] membrane of composition (mg): [KTtt-Bu] (15), PVC (150), DBP (275), and NaTPB (4). This sensor had a Nernstian response (slope, 29.4 ± 0.2 mV decade of activity)
for Zn2+ ions over a wide concentration range (1.4 × 10−7 to 1.0 × 10−1 mol L−1) with a limit of detection of 9.5 × 10−8 mol L−1. It had a relatively fast response time (12 s) and could be used for 3 months without substantial change of the potential.
The membrane sensor had very good selectivity for Zn2+ ions over a wide variety of other cations and could be used in a working pH range of 3.5–7.8. The sensor was also found to
work satisfactorily in partially non-aqueous media and could be successfully used for estimation of zinc at trace levels in
biological and environmental samples.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
Herranz S Ramón-Azcón J Benito-Peña E Marazuela MD Marco MP Moreno-Bondi MC 《Analytical and bioanalytical chemistry》2008,391(5):1801-1812
Specific polyclonal antibodies against s-triazine herbicides were obtained by preparing immunogens coupling home-synthesized haptens derivatives of simazine (6-chloro-N-ethyl-N′-ethyl-1,3,5-triazine-2,4-diamine) to lysine groups of hemocyanin from keyhole limpets and bovine serum albumin carrier proteins.
Three highly sensitive rabbit antisera were obtained and evaluated with a battery of six enzyme tracers derived from triazine
structures in an optimized ELISA format. The antiserum As8 and the HRP-2f tracer, which yield the best assay sensitivity for
simazine (detection limit 0.11 ± 0.02 μg L−1, IC50 0.88 ± 0.04 μg L−1), were applied to the development of a sensitive flow-through immunoassay for the analysis of this herbicide. The automated
assay was based on a direct competitive immunosorbent assay and fluorescence detection. The optimized method presents an IC50 value of 0.35 ± 0.04 μg L−1 with a detection limit of 1.3 ± 0.9 ng L−1 and a dynamic range from 0.010 to 7.5 μg L−1 simazine. The generic nature of the antiserum was shown by good relative cross-reactivities with other triazines such as
atrazine (420%) or propazine (130%) and a lower response to terbutylazine (6.4%) and desethyl-atrazine (2.2%). No cross-reactivity
was obtained for nonrelated pesticides such as 2,4-dichlorophenoxyacetic acid or linuron and the assay could be applied as
a screening method for triazine herbicides. The total analysis time was 30 min per determination and the immunosensor could
be reused for more than 150 cycles without significant loss of activity. The immunosensor has been successfully applied to
the direct analysis of simazine in surface water samples at the nanogram per liter level. The results obtained by comparative
analysis of the immunosensor with a chromatographic procedure for triazines showed a close correspondence. 相似文献