Sensitive detection of polycyclic aromatic hydrocarbons using CdTe quantum dot-modified TiO₂ nanotube array through fluorescence resonance energy transfer.
Sensitive detection of polycyclic aromatic hydrocarbons using CdTe quantum dot-modified TiO₂ nanotube array through fluorescence resonance energy transfer.
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DOI：
10.1021/es101760c
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发表时间：
2010-09
影响因子：
11.4
通讯作者：
Lixia Yang;Beibei Chen;S. Luo;Juanxiu Li;Rong-hua Liu;Q. Cai
中科院分区：
文献类型：
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作者：
Lixia Yang;Beibei Chen;S. Luo;Juanxiu Li;Rong-hua Liu;Q. Cai
首次采用脉冲电沉积法在TiO（2）纳米管上制备了CdTe量子点。利用CdTe量子点修饰TiO（2）NTs制备了一种新型单液滴光学传感器，并将其应用于多环芳烃（PAHs）的荧光共振能量转移（FRET）检测。在270 nm激发时，传感器在370 nm左右显示荧光发射。由于多环芳烃在364/410 nm附近具有吸收/荧光发射，因此在CdTe量子点和多环芳烃之间发生FRET，其中CdTe量子点作为供体，多环芳烃作为受体。灵敏度取决于多环芳烃的环数，在对苯并（a）芘（BaP）的响应中观察到最高的灵敏度。使用FRET，BaP的灵敏度相对于直接荧光光谱提高了约2个数量级。该传感器对苯并（a）芘浓度的对数在400 nM ~ 40 pM范围内呈线性响应，检测限为15 pM，与美国环境保护局规定的饮用水质量标准（15.1 pM）非常接近，表明该传感器可用于多环芳烃的快速扫描。实现的灵敏度是远远高于发表的传感器为基础的方法。由于多环芳烃是基于410-370 nm处的相对荧光强度进行定量的，因此传感器不需要用标准传感器进行校准，避免了传感器之间差异的影响。通过对湘江水体中多环芳烃的分析，验证了该传感器的实用性，采样点的多环芳烃含量范围为0.045 ~ 2.847 ng/L。
CdTe quantum dots (QDs) are prepared on TiO(2) nanotubes (TiO(2) NTs), for the first time, with pulse electrodeposition. A novel single-drop optical sensor is prepared with the CdTe QDs-modified TiO(2) NTs, and applied for the detection of polycyclic aromatic hydrocarbons (PAHs) based on fluorescence resonance energy transfer (FRET). Excited at 270 nm, the sensor shows fluorescence emission at around 370 nm. As PAHs are with absorption/fluorescence emission at around 364/410 nm, FRET happens between the CdTe QDs and PAHs with the CdTe QDs as donors and PAHs as receptors. The sensitivity is dependent on the number of rings of the PAHs, with the highest sensitivity observed in the response to benzo(a)pyrene (BaP). Using FRET, the sensitivity to BaP is enhanced by about 2 orders with respect to the direct fluorescent spectrometry. The proposed sensor shows a linear response to the logarithm of BaP concentration in the range of 400 nM to 40 pM, with a detection limit of 15 pM, which is much close to the quality criteria (15.1 pM) in drinking water set by U.S. Environment Protection, suggesting that the proposed sensor can be used for quick scanning of PAHs. The achieved sensitivity is much higher than that of the published sensor-based methods. As PAHs are quantified based on the relative fluorescence intensity at 410-370 nm, the sensor need no calibration with a standard sensor, avoiding the influence from the sensor-to-sensor difference. The practicability of the sensor is tested by analyzing PAHs in Xiangjiang River water, the PAHs contents ranges from 0.045 to 2.847 ng/L based on the sampling spots.