The Experts below are selected from a list of 2355 Experts worldwide ranked by ideXlab platform
Hui Zhang - One of the best experts on this subject based on the ideXlab platform.
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indirect electrocatalytic determination of choline by monitoring hydrogen peroxide at the choline oxidase prussian blue modified iron phosphate nanostructures
Biosensors and Bioelectronics, 2012Co-Authors: Hui Zhang, Yajing Yin, Chenxin CaiAbstract:Abstract Choline, as a marker of cholinergic activity in brain tissue, is very important in biological and clinical analysis, especially in the clinical detection of the neurodegenerative disorders disease. This work presents an electrochemical approach for the detection of choline based on prussian blue modified iron phosphate nanostructures (PB–FePO4). The obtained nanostructures showed a good catalysis toward the electroreduction of H2O2, and an amperometric choline biosensor was developed by immobilizing choline oxidase on the PB–FePO4 nanostructures. The biosensor exhibited a rapid response (ca. 2 s), low detection limit (0.4 ± 0.05 μM), wide linear range (2 μM to 3.2 mM), high sensitivity (∼75.2 μA mM−1 cm−2), as well as good stability and repeatability. In addition, the common interfering species, such as ascorbic acid, uric acid and 4-acetamidophenol did not cause obvious interference due to the low detection potential (−0.05 V versus Saturated Calomel Electrode). This nanostructure could be used as a promise platform for the construction of other oxidase-based biosensors.
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an electrochemical biosensor for determination of ascorbic acid by cobalt ii phthalocyanine multi walled carbon nanotubes modified glassy carbon Electrode
Sensors and Actuators B-chemical, 2012Co-Authors: Xia Zuo, Hui ZhangAbstract:Abstract Cobalt (II) phthalocyanine–multi-walled carbon nanotubes (CoPc–MWNTs) were synthesized and characterized by energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The cobalt (II) phthalocyanine–multi-walled carbon nanotubes modified glassy carbon (CoPc–MWNTs/GC) Electrode was prepared using the drop coating method. The electrocatalytic performance of the chemically modified Electrode was investigated for ascorbic acid (AA) oxidation. Our results demonstrate that the modified Electrode has excellent electrocatalytic activity towards the oxidation of AA in 0.1 M phosphate buffer solution (PBS, pH 7.0). The oxidation potential of AA was negatively shifted to 0.19 V [vs. Saturated Calomel Electrode (SCE)]. The biosensor tolerated a wide linear concentration range for AA, from 1.0 × 10−5 M to 2.6 × 10−3 M (R = 0.9991), with a detection limit of 1.0 × 10−6 M (S/N = 3). The CoPc–MWNTs modified glassy carbon Electrode has several excellent properties, including a fast response time, high reproducibility and stability.
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low potential detection of endogenous and physiological uric acid at uricase thionine single walled carbon nanotube modified Electrodes
Analytical Chemistry, 2010Co-Authors: Dongxiao Chen, Hui Zhang, Qian Wang, Juan Jin, Hui Wang, Chenxin CaiAbstract:This work develops and validates an electrochemical approach for uric acid (UA) determinations in both endogenous (cell lysate) and physiological (serum) samples. This approach is based on the electrocatalytic reduction of enzymatically generated H2O2 at the biosensor of uricase−thionine−single-walled carbon nanotube/glassy carbon (UOx−Th−SWNTs/GC) with the use of Th−SWNTs nanostructure as a mediator and an enzyme immobilization matrix. The biosensor, which was fabricated by immobilizing UOx on the surface of Th−SWNTs, exhibited a rapid response (ca. 2 s), a low detection limit (0.5 ± 0.05 μM), a wide linear range (2 μM to 2 mM), high sensitivity (∼90 μA mM−1 cm−2), as well as good stability and repeatability. In addition, the common interfering species, such as ascorbic acid, 3,4-dihydroxyphenylacetic acid, 4-acetamidophenol, etc., did not cause any interference due to the use of a low operating potential (−400 mV vs Saturated Calomel Electrode). Therefore, this work has demonstrated a simple and effecti...
Bhim Bali Prasad - One of the best experts on this subject based on the ideXlab platform.
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trace level sensing of creatine in real sample using a zwitterionic molecularly imprinted polymer brush grafted to sol gel modified graphite Electrode
Thin Solid Films, 2010Co-Authors: Amit Kumar Patel, Piyush Sindhu Sharma, Bhim Bali PrasadAbstract:Abstract Zwitterionic molecularly imprinted polymeric chains were tethered to the sol–gel modified graphite Electrode in brush pattern of high density, for the quantitative estimation of creatine at trace level, without any cross reactivity, in real samples. The modified Electrode was activated by preanodization at + 1.4 V (vs. Saturated Calomel Electrode) for the fast ion-exchange recapture of creatine, under mild basic condition (pH 7.1). The detection limit was as low as 1.3 µg mL − 1 (signal/noise = 3) employing differential pulse, cathodic stripping technique.
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electrochemical sensor for uric acid based on a molecularly imprinted polymer brush grafted to tetraethoxysilane derived sol gel thin film graphite Electrode
Materials Science and Engineering: C, 2009Co-Authors: Amit Kumar Patel, Piyush Sindhu Sharma, Bhim Bali PrasadAbstract:Abstract Determination of uric acid in human serum and urine is useful to provide treatment guidelines to hyperuricemic patients. An electrochemical sensor was developed for selective and quantitative recognition of uric acid by using a preanodised sol-gel coated graphite Electrode with a molecularly imprinted polymer brush of poly(melamine–co-chloranil) grafted to its exterior surface. During a preconcentration step at (+ 2.0 V versus Saturated Calomel Electrode), the encapsulated analyte recapture involved hydrophobically induced hydrogen-bondings in outwardly exposed MIP cavities in aqueous environment (pH 7.0), instantly oxidised as dications, and then cathodically stripped off as corresponding lactam responding differential pulse, cathodic stripping voltammetric signal. The uric acid was selectively detected without any cross reactivity in the windows of 14.56–177.42 µg mL− 1 (aqueous medium), 4.78–106.96 µg mL− 1 (blood serum), and 7.81–148.42 µg mL− 1 (urine) indicating detection limits in the range of 3.71–4.10 µg mL− 1 (3σ, RSD = 1.9%).
Chenxin Cai - One of the best experts on this subject based on the ideXlab platform.
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indirect electrocatalytic determination of choline by monitoring hydrogen peroxide at the choline oxidase prussian blue modified iron phosphate nanostructures
Biosensors and Bioelectronics, 2012Co-Authors: Hui Zhang, Yajing Yin, Chenxin CaiAbstract:Abstract Choline, as a marker of cholinergic activity in brain tissue, is very important in biological and clinical analysis, especially in the clinical detection of the neurodegenerative disorders disease. This work presents an electrochemical approach for the detection of choline based on prussian blue modified iron phosphate nanostructures (PB–FePO4). The obtained nanostructures showed a good catalysis toward the electroreduction of H2O2, and an amperometric choline biosensor was developed by immobilizing choline oxidase on the PB–FePO4 nanostructures. The biosensor exhibited a rapid response (ca. 2 s), low detection limit (0.4 ± 0.05 μM), wide linear range (2 μM to 3.2 mM), high sensitivity (∼75.2 μA mM−1 cm−2), as well as good stability and repeatability. In addition, the common interfering species, such as ascorbic acid, uric acid and 4-acetamidophenol did not cause obvious interference due to the low detection potential (−0.05 V versus Saturated Calomel Electrode). This nanostructure could be used as a promise platform for the construction of other oxidase-based biosensors.
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low potential detection of endogenous and physiological uric acid at uricase thionine single walled carbon nanotube modified Electrodes
Analytical Chemistry, 2010Co-Authors: Dongxiao Chen, Hui Zhang, Qian Wang, Juan Jin, Hui Wang, Chenxin CaiAbstract:This work develops and validates an electrochemical approach for uric acid (UA) determinations in both endogenous (cell lysate) and physiological (serum) samples. This approach is based on the electrocatalytic reduction of enzymatically generated H2O2 at the biosensor of uricase−thionine−single-walled carbon nanotube/glassy carbon (UOx−Th−SWNTs/GC) with the use of Th−SWNTs nanostructure as a mediator and an enzyme immobilization matrix. The biosensor, which was fabricated by immobilizing UOx on the surface of Th−SWNTs, exhibited a rapid response (ca. 2 s), a low detection limit (0.5 ± 0.05 μM), a wide linear range (2 μM to 2 mM), high sensitivity (∼90 μA mM−1 cm−2), as well as good stability and repeatability. In addition, the common interfering species, such as ascorbic acid, 3,4-dihydroxyphenylacetic acid, 4-acetamidophenol, etc., did not cause any interference due to the use of a low operating potential (−400 mV vs Saturated Calomel Electrode). Therefore, this work has demonstrated a simple and effecti...
Taku Hasobe - One of the best experts on this subject based on the ideXlab platform.
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organized assemblies of single wall carbon nanotubes and porphyrin for photochemical solar cells charge injection from excited porphyrin into single walled carbon nanotubes
Journal of Physical Chemistry B, 2006Co-Authors: Taku Hasobe, Shunichi Fukuzumi, Prashant V KamatAbstract:Photochemical solar cells have been constructed from organized assemblies of single-walled carbon nanotubes (SWCNT) and protonated porphyrin on nanostructured SnO2 Electrodes. The protonated form of porphyrin (H4P2+) and SWCNT composites form 0.5−3.0 μm-sized rodlike structures and they can be assembled onto nanostructured SnO2 films [optically transparent Electrode OTE/SnO2] by an electrophoretic deposition method. These organized assemblies are photoactive and absorb strongly in the entire visible region. The incident photon to photocurrent efficiency (IPCE) of OTE/SnO2/SWCNT-H4P2+ is ∼13% at an applied potential of 0.2 V versus Saturated Calomel Electrode. Femtosecond pump−probe spectroscopy experiments confirm the decay of the excited porphyrin in the SWCNT−H4P2+ assembly as it injects electrons into SWCNT. The dual role of SWCNT in promoting photoinduced charge separation and facilitating charge transport is presented.
Amit Kumar Patel - One of the best experts on this subject based on the ideXlab platform.
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trace level sensing of creatine in real sample using a zwitterionic molecularly imprinted polymer brush grafted to sol gel modified graphite Electrode
Thin Solid Films, 2010Co-Authors: Amit Kumar Patel, Piyush Sindhu Sharma, Bhim Bali PrasadAbstract:Abstract Zwitterionic molecularly imprinted polymeric chains were tethered to the sol–gel modified graphite Electrode in brush pattern of high density, for the quantitative estimation of creatine at trace level, without any cross reactivity, in real samples. The modified Electrode was activated by preanodization at + 1.4 V (vs. Saturated Calomel Electrode) for the fast ion-exchange recapture of creatine, under mild basic condition (pH 7.1). The detection limit was as low as 1.3 µg mL − 1 (signal/noise = 3) employing differential pulse, cathodic stripping technique.
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electrochemical sensor for uric acid based on a molecularly imprinted polymer brush grafted to tetraethoxysilane derived sol gel thin film graphite Electrode
Materials Science and Engineering: C, 2009Co-Authors: Amit Kumar Patel, Piyush Sindhu Sharma, Bhim Bali PrasadAbstract:Abstract Determination of uric acid in human serum and urine is useful to provide treatment guidelines to hyperuricemic patients. An electrochemical sensor was developed for selective and quantitative recognition of uric acid by using a preanodised sol-gel coated graphite Electrode with a molecularly imprinted polymer brush of poly(melamine–co-chloranil) grafted to its exterior surface. During a preconcentration step at (+ 2.0 V versus Saturated Calomel Electrode), the encapsulated analyte recapture involved hydrophobically induced hydrogen-bondings in outwardly exposed MIP cavities in aqueous environment (pH 7.0), instantly oxidised as dications, and then cathodically stripped off as corresponding lactam responding differential pulse, cathodic stripping voltammetric signal. The uric acid was selectively detected without any cross reactivity in the windows of 14.56–177.42 µg mL− 1 (aqueous medium), 4.78–106.96 µg mL− 1 (blood serum), and 7.81–148.42 µg mL− 1 (urine) indicating detection limits in the range of 3.71–4.10 µg mL− 1 (3σ, RSD = 1.9%).
