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1.
T. M. Wijendra Jayalath Bandara Piyasiri Ekanayake M. A. K. Lakshman Dissanayake Ingvar Albinsson Bengt-Erik Mellander 《Journal of Solid State Electrochemistry》2010,14(7):1221-1226
Various iodide ion conducting polymer electrolytes have been studied as candidate materials for fabricating photoelectrochemical
(PEC) solar cells and energy storage devices. In this study, enhanced ionic conductivity values were obtained for the ionic
liquid tetrahexylammonium iodide containing polyethylene oxide (PEO)-based plasticized electrolytes. The analysis of thermal
properties revealed the existence of two phases in the electrolyte, and the conductivity measurements showed a marked conductivity
enhancement during the melting of the plasticizer-rich phase of the electrolyte. Annealed electrolyte samples showed better
conductivity than nonannealed samples, revealing the existence of hysteresis. The optimum conductivity was shown for the electrolytes
with PEO:salt = 100:15 mass ratio, and this sample exhibited the minimum glass transition temperature of 72.2 °C. For this
optimum PEO to salt ratio, the conductivity of nonannealed electrolyte was 4.4 × 10−4 S cm−1 and that of the annealed sample was 4.6 × 10−4 S cm−1 at 30 °C. An all solid PEC solar cell was fabricated using this annealed electrolyte. The short circuit current density (I
SC), the open circuit voltage (V
OC), and the power conversion efficiency of the cell are 0.63 mA cm−2, 0.76 V, and 0.47% under the irradiation of 600 W m−2 light. 相似文献
2.
Li Z Yan M Li Z Vuki M Wu D Liu F Zhong W Zhang L Xu D 《Analytical and bioanalytical chemistry》2012,403(5):1373-1384
The estrogen receptor (ER) is regarded as a significant drug target because of its important physical and pathological function.
In this article, we describe a novel screening method to obtain agonists and antagonists of ER. ER was immobilized onto an
aldehyde-modified glass slide. The affinity of Cy3-labeled estradiol for ER protein microarrays was then determined. Two libraries,
one containing 29 synthetic compounds and the other with 384 natural products that served as a model, were screened to find
new ligands for ER. The IC50 values obtained for tamoxifen and raloxifene were consistent with those found in the literature (4.85 × 10−7 M versus 1.74~4.23 × 10−7 M and 7.58 × 10−8 M versus 0.89~5.84 × 10−8 M, respectively). Finally, 65 active ligands (5 synthetic compounds and 60 natural products) of ER were identified. This
novel method gave identical results to a conventional fluorescence polarization assay, thus verifying the accuracy of this
simultaneous multireceptor screening method based on protein microarrays. The presented method is sensitive, accurate, and
reliable, and shows great potential for use in high-throughput drug-screening research. 相似文献
3.
Atsushi Shoji Erika Sugimoto Sayaka Orita Keiichiro Nozawa Akio Yanagida Yoichi Shibusawa Masao Sugawara 《Analytical and bioanalytical chemistry》2010,397(3):1377-1381
We describe a reusable liposome array based on the formation of cleavable disulfide cross-links between liposomes and the
surface of a glass slip. The N-succinimidyl 3-(2-pyridyldithio)-propionate (SPDP)-modified liposomes encapsulating a pH-sensitive fluorescence dye were
immobilized on a 3-mercaptopropyltrimethoxysilane (MTS)-modified glass slip through the formation of disulfide bonds. The
regeneration of a used slip was performed by the lysis of immobilized liposomes with Triton X-100 and the cleavage of disulfide
bonds by reduction with TCEP, followed by immobilization of SPDP-modified liposomes. The regeneration steps did not affect
the fluorescence intensity of re-immobilized liposomes. The liposome array was applied to simultaneous quantification of growth
hormone related peptides, i.e., GHRF and somatostatin, in a mixture. After optimizing the assay condition, the method allowed
quantification of GHRF and somatostatin in concentration ranges from 0.5 × 10−9 to 0.5 × 10−7 g/mL with detection limits of 2 × 10−10 and 3 × 10−10 g/mL, respectively. 相似文献
4.
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
5.
Theodora J. Stewart Jean-Huei Yau Mary M. Allen Daniel J. Brabander Nolan T. Flynn 《Colloid and polymer science》2009,287(9):1033-1040
Chronic exposure to Pb2+ above the 15-μg/L US Environmental Protection Agency action level for drinking water has been shown to cause a host of health
problems in humans. Thus, it is important to study new methods available for the treatment and removal of Pb2+ from drinking water and wastewater, where elevated levels of heavy metals are found. Alginate-based beads represent one such
possible method for heavy metal removal. The impact of alginate density on the equilibrium and kinetics of Pb2+ sorption onto hydrogel beads was investigated using Ca-alginate beads ranging from 1% to 8% (w/v) and exposed to Pb2+ concentrations ranging from 100 to 1,000 mg/L. When Ca-alginate beads were characterized using Fourier transform infrared
analysis, the carboxylic acid groups of the mannuronate and guluronate residues in alginate were the primary functional groups
that interacted with Pb2+. Hydration of Ca-alginate beads was also examined and found to decrease as Ca-alginate density increased. A positive correlation
was observed between Ca-alginate hydration and Pb2+ sorption. Sorption of Pb2+ was fast, reaching equilibrium after approximately 4 h, and is well described by the Langmuir adsorption isotherm. Maximum
sorption capacities for 1%, 4%, and 8% beads were 500 ± 100, 360 ± 30, and 240 ± 20 mg/g (dry weight), respectively. The kinetics
of sorption were best described by the pseudo-second-order Lagergren model, with rate constants determined as 3.2 ± 0.1 × 10−4, 1.0 ± 0.1 × 10−4, and 1.6 ± 0.1 × 10−4 g mg−1 min−1 for 1%, 4%, and 8% beads, respectively. 相似文献
6.
Sayed Medhi Ghoreishi Mohsen Behpour Mohammad Hassan Motaghedi Fard 《Journal of Solid State Electrochemistry》2012,16(1):179-189
In this work, we investigate the electrochemical activity of dopamine (DA) and uric acid (UA) using both a bare and a modified
carbon paste electrode as the working electrode, with a platinum wire as the counter electrode and a silver/silver chloride
(Ag/AgCl) as the reference electrode. The modified carbon paste electrode consists of multi-walled carbon nanotubes (>95%)
treated with α-cyclodextrine, resulting in an electrode that exhibits a significant catalytic effect toward the electro-chemical
oxidation of DA in a 0.2-M Britton–Robinson buffer solution (pH 5.0). The peak current increases linearly with the DA concentration
within the molar concentration ranges of 2.0 × 10−6 to 5.0 × 10−5 M and 5.0 × 10−5 to 1.9 × 10−4 M. The detection limit (signal to noise >3) for DA was found to be 1.34 × 10−7 M, respectively. In this work, voltammetric methods such as cyclic voltammetry, chronoamperometry, chronocuolometry, differential
pulse and square wave voltammetry, and linear sweep and hydrodynamic voltammetry were used. Cyclic voltammetry was used to
investigate the redox properties of the modified electrode at various scan rates. The diffusion coefficient (D, cm2 s−1 = 3.05 × 10−5) and the kinetic parameters such as the electron transfer coefficient (α = 0.51) and the rate constant (k, cm3 mol−1 s−1 = 1.8 × 103) for DA were determined using electrochemical approaches. By using differential pulse voltammetry for simultaneous measurements,
we obtained two peaks for DA and UA in the same solution, with the peak separation approximately 136 mV. The average recovery
was measured at 102.45% for DA injection. 相似文献
7.
A new electrochemiluminescence (ECL) method based on the proximity-dependent surface hybridization assay and Ru(bpy)32+-doped silica nanoparticles (Ru-DSNPs) as labels were proposed for detecting DNA. The hybridization process involves two steps:
firstly, the 3′ thiolated capture probe was self-assembled on the gold electrode. Secondly, the proximity-dependent surface
hybridization assay was carried out. This proximity-dependent surface hybridization assay depended on the simultaneous recognition
of a target DNA by a capture probe and Ru-DSNP-labeled probe and the formation of a duplex complex, which results in the luminophor
approach to the electrode surface. Thus, sensitive ECL signals were obtained. Under optimum conditions, the intensity of the
ECL of Ru-DSNPs was linearly related to the concentration of the target sequence in the range of 2.0 × 10−15 to 2.0 × 10−11 mol/L. The detection limit was 1.0 × 10−15 mol/L (S/N = 3). 相似文献
8.
Mário A. P. Nunes Hélder Vila-Real Pedro C. B. Fernandes Maria H. L. Ribeiro 《Applied biochemistry and biotechnology》2010,160(7):2129-2147
A synthetic polymer, polyvinyl alcohol (PVA), a cheap and nontoxic synthetic polymer to organism, has been ascribed for biocatalyst
immobilization. In this work PVA–alginate beads were developed with thermal, mechanical, and chemical stability to high temperatures
(<80 °C). The combination of alginate and bead treatment with sodium sulfate not only prevented agglomeration but produced
beads of high gel strength and conferred enzyme protection from inactivation by boric acid. Naringinase from Penicillium decumbens was immobilized in PVA (10%)–alginate beads with three different sizes (1–3 mm), at three different alginate concentrations
(0.2–1.0%), and these features were investigated in terms of swelling ratio within the beads, enzyme activity, and immobilization
yield during hydrolysis of naringin. The pH and temperature optimum were 4.0 and 70 °C for the PVA–alginate-immobilized naringinase.
The highest naringinase activity yield in PVA (10%)–alginate (1%) beads of 2 mm was 80%, at pH 4.0 and 70 °C. The Michaelis
constant (K
Mapp) and the maximum reaction velocity (V
maxapp) were evaluated for both free (K
Mapp = 0.233 mM; V
maxapp = 0.13 mM min−1) and immobilized naringinase (K
Mapp = 0.349 mM; V
maxapp = 0.08 mM min−1). The residual activity of the immobilized enzyme was followed in eight consecutive batch runs with a retention activity
of 70%. After 6 weeks, upon storage in acetate buffer pH 4 at 4 °C, the immobilized biocatalyst retained 90% of the initial
activity. These promising results are illustrative of the potential of this immobilization strategy for the system evaluated
and suggest that its application may be effectively performed for the entrapment of other biocatalysts. 相似文献
9.
Zirconium (IV) was determined spectrophotometrically by reaction with quercetin as primary ligand and oxalate as secondary
ligand. Polyvinylpyrrolidone (PVP) was used as protective colloid to solubilize the formed zirconium quercetin oxalate ternary
complex. The molar absorptivity of the 1:3:1 (zirconium–quercetin–oxalate) complex is 7.31 × 104 L·mol−1 cm−1 at 430 nm with a stability constant of 8.2 × 1020 and its detection limit is 0.16 mg/L. Beer’s law is rectilinear up to 1.46 mg/L of zirconium (IV). The sensitivity index
is 1.25 ng cm−2.
The reaction of aluminium (III) with quercetin in presence of PVP as a surfactant has been studied spectrophotometrically.
The molar absorptivity of the 1:3 (aluminium–quercetin) complex is 8.09 × 104 × L·mol−1·cm−1 at 433 nm, its stability constant is 2.6 × 1013 with sensitivity index of 0.33 ng·cm−2 and its detection limit is 0.08 mg/L. The optimal conditions for the quantitative determination of zirconium and aluminium
were studied. The proposed methods are examined by statistical analysis of the experimental data. The methods are free from
interference of most cations and anions. The proposed methods have been used to determine zirconium and aluminium in industrial
waste water.
Received May 30, 2001; accepted November 2, 2001; published online July 15, 2002 相似文献
10.
D. M. Ortega-Sotelo J. G. Gonzalez-Rodriguez M. A. Neri-Flores M. Casales L. Martinez A. Martinez-Villafañe 《Journal of Solid State Electrochemistry》2011,15(9):1997-2004
The corrosion inhibition of X-70 pipeline steel in saltwater saturated with CO2 at 50 °C with carboxyamido imidazoline has been evaluated by using electrochemical techniques. Techniques included polarization
curves, linear polarization resistance, electrochemical impedance, and electrochemical noise measurements. Inhibitor concentrations
were 0, 1.6 × 10−5, 3.32 × 10−5, 8.1 × 10−5, 1.6 × 10−4, and 3.32 × 10−4 mol l−1. All techniques showed that the best corrosion inhibition was obtained by adding 8.1 × 10−5 mol l−1 of carboxyamido imidazoline. For inhibitor concentrations higher than 8.1 × 10−5 mol l−1 a desorption process occurs, and an explanation has been given for this phenomenon. 相似文献
11.
Shirong Yuan Ruo Yuan Yaqin Chai Ying Zhuo Xia Yang Yali Yuan 《Applied biochemistry and biotechnology》2010,162(8):2189-2196
In this work, an enzyme biosensor based on the immobilization of horseradish peroxidase (HRP) on SiO2/BSA/Au/thionine/nafion-modified gold electrode was fabricated successfully. Firstly, nafion was dropped on the surface of
the gold electrode to form a nafion film followed by chemisorption of thionine (Thi) as an electron mediator via the ion-exchange
interaction between the Thi and nafion. Subsequently, the SiO2/BSA/Au composite nanoparticles were assembled onto Thi film through the covalent bounding with the amino groups of Thi. Finally,
HRP was immobilized on the SiO2/BSA/Au composite nanoparticles due to the covalent conjugation to construct an enzyme biosensor. The surface topographies
of the SiO2/BSA/Au composite nanoparticles were investigated by using scanning electronic microscopy. The stepwise self-assemble procedure
of the biosensor was further characterized by means of cyclic voltammetry and chronoamperometry. The enzyme biosensor showed
high sensitivity, good stability and selectivity, a wide linear response to hydrogen peroxide (H2O2) in the range of 8.0 × 10-6 ∼ 3.72 × 10-3 mol/L, with a detection limit of 2.0 × 10-6 mol/L. The Michaelies-Menten constant KMapp K_M^{app} value was estimated to be 2.3 mM. 相似文献
12.
The electrochemical behaviors of metol on an ionic liquid N-butylpyridinium hexafluorophosphate modified carbon paste electrode (IL-CPE) were studied in this paper. The results indicated
that a pair of well-defined quasi-reversible redox peaks of metol appeared with the decrease of overpotential and the increase
of redox peak current, which was the characteristics of electrocatalytic oxidation. The electrocatalytic mechanism was discussed
and the electrochemical parameters were calculated with results of the charge-transfer coefficient (α) as 0.45, the electrode reaction rate constant (k
s) as 4.02 × 10−3 s−1, and the diffusion coefficient (D) as 6.35 × 10−5 cm2/s. Under the optimal conditions, the anodic peak current was linear with the metol concentration in the range of 5.0 × 10−6 ∼ 1.0 × 10−3 mol/L (n = 11, γ = 0.994) and the detection limit was estimated as 2.33 × 10−6 mol/L (3σ). The proposed method was successfully applied to determination of metol content in synthetic samples and photographic solutions. 相似文献
13.
Letao Wang Yan Zhang Yongling Du Daban Lu Yuzhen Zhang Chunming Wang 《Journal of Solid State Electrochemistry》2012,16(4):1323-1331
Simultaneous determination of catechol (CC) and hydroquinone (HQ) were investigated by voltammetry based on glassy carbon
electrode (GCE) modified by poly (diallyldimethylammonium chloride) (PDDA) functionalized graphene (PDDA-G). The modified
electrode showed excellent sensitivity and selectivity properties for the two dihydroxybenzene isomers. In 0.1 mol/L phosphate
buffer solution (PBS, pH 7.0), the oxidation peak potential difference between CC and HQ was 108 mV, and the peaks on the
PDDA-G/GCE were three times as high as the ones on graphene-modified glass carbon electrode. Under optimized conditions, the
PDDA-G/GCE showed wide linear behaviors in the range of 1 × 10−6−4 × 10−4 mol/L for CC and 1 × 10−6−5 × 10−4 mol/L for HQ, with the detection limits 2.0 × 10−7 mol/L for CC and 2.5 × 10−7 mol/L for HQ (S/N = 3) in mixture, respectively. Some kinetic parameters, such as the electron transfer number (n), charge transfer coefficient (α), and the apparent heterogeneous electron transfer rate constant (k
s), were calculated. The proposed method was applied to simultaneous determine CC and HQ in real water samples of Yellow River
with satisfactory results. 相似文献
14.
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
15.
Ji Won Lee Hyang Bong Lee Kwan Kim Kuan Soo Shin 《Analytical and bioanalytical chemistry》2010,397(2):557-562
A novel method to deposit a highly surface-enhanced Raman scattering (SERS) active silver film onto the inside surface of
a glass capillary is developed. Firstly, Ag sol was synthesized by the reaction of AgNO3 with poly-(ethylenimine) (PEI), and then toluene and benzenethiol (BT) were added into the sol. The mixture was flowed through
the glass capillary to obtain the SERS-active Ag film-coated glass capillary. The SERS activity of the Ag-coated capillary
was dependent on the amount of PEI and BT used. In addition, BT could be easily desorbed from the Ag surface by treating it
with a borohydride solution, maintaining the initial SERS activity. The SERS enhancement factor at 632.8-nm excitation was
estimated to be on the order of 106. The detection limits of adenine and dipicolinic acid were then as low as 1.0 × 10−8 and 1.0 × 10−7 M, respectively, based on an S/N ratio of 3. This clearly suggests that the Ag-coated capillary is an invaluable device for
the analysis of effluent chemicals by SERS. 相似文献
16.
Voltammetric sensor for glutathione determination based on ferrocene-modified carbon paste electrode
Jahan Bakhsh Raoof Reza Ojani Mansureh Kolbadinezhad 《Journal of Solid State Electrochemistry》2009,13(9):1411-1416
The electrocatalytic oxidation of glutathione (GSH) has been studied at the surface of ferrocene-modified carbon paste electrode
(FMCPE). Cyclic voltammetry (CV), double potential step chronoamperometry, and differential pulse voltammetry (DPV) techniques
were used to investigate the suitability of incorporation of ferrocene into FMCPE as a mediator for the electrocatalytic oxidation
of GSH in buffered aqueous solution. Results showed that pH 7.00 is the most suitable for this purpose. In the optimum condition
(pH 7.00), the electrocatalytic ability of about 480 mV can be found and the heterogeneous rate constant of catalytic reaction
was calculated as . Also, the diffusion coefficient of glutathione, D, was found to be 3.61 × 10–5 cm2 s−1. The electrocatalytic oxidation peak current of glutathione at the surface of this modified electrode was linearly dependent
on the GSH concentration and the linear analytical curves were obtained in the ranges of 3.2 × 10–5 M–1.6 × 10–3 M and 2.2 × 10–6 M–3.5 × 10–3 M with cyclic voltammetry and differential pulse voltammetry methods, respectively. The detection limits (3σ) were determined as 1.8 × 10–5 M and 2.1 × 10–6 M using CV and DPV, respectively. Finally, the electrocatalytic oxidation of GSH at the surface of this modified electrode
can be employed as a new method for the voltammetric determination of glutathione in real samples such as human plasma. 相似文献
17.
Shafiquzzaman Siddiquee Nor Azah Yusof Abu Bakar Salleh Soon Guan Tan Fatimah Abu Bakar 《Journal of Solid State Electrochemistry》2012,16(1):273-282
Electrochemical DNA biosensor was successfully developed by depositing the ionic liquid (e.g., 1-ethyl-3-methylimidazolium
trifluoromethanesulfonate ([EMIM][Otf])), ZnO nanoparticles, and chitosan (CHIT) nanocomposite membrane on a modified gold
electrode (AuE). The electrochemical properties of the [EMIM][Otf]/ZnO/CHIT/AuE for detection of DNA hybridization were studied.
Under optimal conditions using cyclic voltammetry, the target DNA sequences could be detected in the concentration range of
1.0 × 10−18 to 1.82 × 10−4 mol L−1, and with the detection limit of 1.0 × 10−19 mol L−1. This DNA biosensor detection approaches provide a quick, sensitive, and convenient method to be used in the identification
of Trichoderma harzianum. 相似文献
18.
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
19.
Jahan Bakhsh Raoof Reza Ojani Maryam Ramine 《Journal of Solid State Electrochemistry》2009,13(9):1311-1319
A p-duroquinone (tetramethyl-p-benzoquinone) modified carbon paste electrode (DMCPE) was employed to study the electrocatalytic reduction of nitrite in
aqueous solutions using cyclic voltammetry (CV), double potential-step chronoamperometry, and differential pulse voltammetry
(DPV). It has found that under an optimum condition (pH 1.00), the reduction of nitrite at the surface of DMCPE occurs at
a potential of about 660 mV less negative than that of an unmodified carbon paste electrode (CPE). The catalytic rate constant,
k′h, based on Andrieux and Saveant theoretical model was calculated as for scan rate 10 mV s-1. Also, the apparent diffusion coefficient, D
app, was found as 2.5 × 10–10 and 3.61 × 10–5 cm2 s-1
for p-duroquinone in carbon paste matrix and nitrite in aqueous buffered solution, respectively. The values for αnα were estimated to be −0.65 and −0.19 for the reduction of nitrite at the surface of DMCPE and CPE, respectively. The electrocatalytic
reduction peak currents showed a linear dependence on the nitrite concentration, and a linear analytical curve was obtained
in the ranges of 5.0 × 10–5 M to 8.0 × 10–3 M and 6.0 × 10–6 M to 8.0 × 10–4 M of nitrite concentration with CV and DPV methods, respectively. The detection limits (2σ) were determined as 2.5 × 10–5 M and 4.3 × 10–6 M by CV and DPV methods. This method was also applied as a simple, selective and precise method for determination of nitrite
in real samples (the weak liquor from the wood and paper factory of Mazandaran province in Iran) by using a standard addition
method. 相似文献
20.
Caglar P Tuncel SA Malcik N Landers JP Ferrance JP 《Analytical and bioanalytical chemistry》2006,386(5):1303-1312
A newly designed glass-PDMS microchip-based sensor for use in the determination of Ca2+ ions has been developed, utilizing reflectance measurements from arsenazo III (1,8-dihydroxynaphthalene-3,6-disulfonic acid-2,7-bis[(azo-2)-phenyl
arsenic acid]) immobilized on the surface of polymer beads. The beads, produced from cross-linked poly(p-chloromethylstyrene) (PCMS), were covalently modified with polyethylenimine (PEI) to which the Arsenazo III could be adsorbed.
The maximum amount of Arsenazo III which could be immobilized onto the PEI-attached PCMS beads was found to be 373.71 mg g−1 polymer at pH 1. Once fabricated, the beads were utilized at the detection point of the microfluidic sensor device with a
fiber optic assembly for reflectance measurements. Samples were mobilized past the detection point in the sensor where they
interact with the immobilized dye. The sensor could be regenerated and re-used by rinsing with HCl solution. The pH, voltage,
linear range, and the effect of interfering ions were evaluated for Ca2+ determination using this microchip sensor. At the optimum potential, 0.8 kV, and pH 9.0, the linear range of the microchip
sensor was 3.57 × 10−5 – 5.71 × 10−4 M Ca2+, with a limit of detection (LOD) of 2.68 × 10−5 M. The microchip biosensor was then applied for clinical analysis of calcium ions in serum with good results.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献