Fabrication and characterization of Cu(OH)2/CuO nanowires as a novel sensitivity enhancer of the luminol–H2O2 chemiluminescence system: determination of cysteine in human plasma
Fabrication and characterization of Cu(OH)2/CuO nanowires as a novel sensitivity enhancer of the luminol–H2O2 chemiluminescence system: determination of cysteine in human plasma
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DOI：
10.1039/c5ra21085b
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发表时间：
2016-01
期刊：
影响因子：
3.9
通讯作者：
A. Mokhtari;A. Goudarzi;M. Benam;S. M. Langroodi;S. Karimmohammad;Mohsen Keyvanfard
中科院分区：
文献类型：
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作者：
A. Mokhtari;A. Goudarzi;M. Benam;S. M. Langroodi;S. Karimmohammad;Mohsen Keyvanfard
为提高鲁米诺-双氧水化学发光体系测定半胱氨酸的固有灵敏度，提出了一种新的化学发光反应策略。结果表明，在自制的氢氧化铜/氧化铜纳米线(Cu(OH)2/CuO-NWS)存在下，鲁米诺-H_2O_2体系中半胱氨酸的化学发光强度明显增强。在胶体Cu(OH)2/CuO-NWS存在下，半胱氨酸的测定灵敏度提高了约3-6倍。用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)和紫外可见光谱(UV-Vis)对其结构、形貌和光学性能进行了表征。傅里叶变换红外光谱(FT-IR)研究了合成的纳米粒子中有机化合物和/或其他化合物的存在。为了探讨化学发光的机理，进行了紫外-可见光谱、荧光光谱和化学发光光谱的研究。结果表明，半胱氨酸化学发光强度的增强是由于鲁米诺、H_2O_2和半胱氨酸被吸附在纳米颗粒表面，促进了电子和能量的传递过程。化学发光光谱表明，该发光体为激发态3-氨基邻苯二甲酸根阴离子(3-AP2−*，鲁米诺的氧化产物)。此外，UV-Vis吸收光谱表明，吸附的半胱氨酸在纳米粒子表面非常容易被氧化，生成的产物与O2·−自由基一起产生更多的3-AP2−*阴离子。因此，在制备的NWS存在的情况下，可以产生更高的化学发光强度。这种增强作用在鲁米诺-H_2O_2-纳米颗粒的化学发光体系中尚未见到。基于这些发现，建立了一种快速、灵敏的半胱氨酸测定方法。在最佳条件下，半胱氨酸的浓度在0.8×10−9~8.0×10−8moL L−1和8×10−8~1.0×10−6molL−1范围内与化学发光强度呈良好的线性关系，检出限为0.6 9×10−9moL L−1，相对标准偏差为5.7%(n=11)，50×10−9moL L−1的相对标准偏差为5.7%。该方法已成功地用于人血浆和人工合成注射样品中半胱氨酸的灵敏测定。
This investigation is a novel chemiluminescence (CL) reaction strategy to enhance the inherent sensitivity of the luminol–H2O2 CL system for the determination of cysteine. It was found that CL intensity of cysteine in the luminol–H2O2 system could be enhanced strongly in the presence of our synthesized copper hydroxide/copper oxide nanowires (Cu(OH)2/CuO NWs). About 3–6 fold improvement in the sensitivity was observed when cysteine was determined in the presence of colloidal Cu(OH)2/CuO NWs. Structural, morphological and optical properties of the Cu(OH)2/CuO NWs were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and ultraviolet-visible (UV-Vis) spectroscopy. Fourier Transform Infrared Spectroscopy (FT-IR) studies were done to investigate the presence of organic and/or other compounds in the synthesized NWs. In order to explore the CL mechanism, UV-Vis, fluorescence, and CL spectra studies were carried out. It is suggested that the enhancement in the CL intensity of cysteine is due to the fact that luminol, H2O2 and cysteine could be adsorbed on the surface of NWs and all the electron and the energy transfer processes could be facilitated on the surface of NWs. The CL spectra showed that, the luminophor is the excited-state 3-aminophthalate anion (3-AP2−*, the oxidation product of luminol). Moreover, UV-Vis absorption spectra showed that adsorbed cysteine could be oxidized very easy on the surface of NWs and the resulting product along with O2˙− radicals generate more 3-AP2−* anions. Therefore, higher CL intensities could be produced in the presence of prepared NWs. This enhancement effect has not been seen in the CL system of luminol–H2O2–nanoparticles up to now. Based on these findings, a rapid and sensitive assay was developed for the determination of cysteine. Under the optimum conditions, the CL intensity was proportional to the concentration of cysteine in the ranges 0.8 × 10−9 to 8.0 × 10−8 mol L−1 and 8 × 10−8 to 1.0 × 10−6 mol L−1. The limit of detection was 0.69 × 10−9 mol L−1 and percent of relative standard deviations for 50 × 10−9 mol L−1 cysteine (n = 11) was 5.7%. The proposed method was applied successfully for the sensitive determination of cysteine in human plasma and synthesized injection samples.