Saenwong Khanitta, Nuengmatcha Prawit, Sricharoen Phitchan, Limchoowong Nunticha, Chanthai Saksit
Materials Chemistry Research Center, Department of Chemistry, Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University Khon Kaen 40002 Thailand
Nanomaterials Chemistry Research Unit, Department of Chemistry, Faculty of Science and Technology, Nakhon Si Thammarat Rajabhat University Nakhon Si Thammarat 80280 Thailand.
RSC Adv. 2018 Mar 14;8(18):10148-10157. doi: 10.1039/c7ra13432k. eCollection 2018 Mar 5.
Synthesis and characterization of graphene quantum dots (GQDs) simultaneously doped with 1% glutathione (GSH-GQDs) by pyrolysis using citric acid rich-lime oil extract as a starting material. The excitation wavelength ( = 337 nm) of the obtained GSH-GQD solution is blue shifted from that of bare GQDs ( = 345 nm), with the same emission wavelength ( = 430 nm) indicating differences in the desired N and S matrices decorating the carbon based nanoparticles, without any background effect of both ionic strength and masking agent. For highly Fe-sensitive detection under optimum conditions, acetate buffer at pH 4.0 in the presence of 50 μM HO, the linearity range was 1.0-150 μM ( = 0.9984), giving its calibration curve: = 34.934 + 169.61. The LOD and LOQ were found to be 0.10 and 0.34 μM, respectively. The method's precisions expressed in terms of RSDs for repeatability ( = 3 × 3 for intra-day analysis) were 2.03 and 3.17% and for reproducibility ( = 5 × 3 for inter-day analysis) were 3.11 and 4.55% for Fe and Fe, respectively. The recoveries of the method expressed as the mean percentage ( = 3) were found in the ranges of 100.1-104.1 and 98.08-102.7% for Fe and Fe, respectively. The proposed method was then implemented satisfactorily for trace determination of iron speciation in drinking water.
以富含柠檬酸的石灰油提取物为起始原料，通过热解同时合成并表征了掺杂1%谷胱甘肽的石墨烯量子点（GSH-GQDs）。所得GSH-GQD溶液的激发波长（λex = 337 nm）相对于裸GQDs（λex = 345 nm）发生蓝移，发射波长相同（λem = 430 nm），这表明修饰在碳基纳米颗粒上的所需N和S基质存在差异，且不受离子强度和掩蔽剂的任何背景影响。在最佳条件下，于pH 4.0的醋酸盐缓冲液中，在50 μM H2O2存在下进行高灵敏度铁检测时，线性范围为1.0 - 150 μM（R2 = 0.9984），其校准曲线为：y = 34.934 + 169.61x。检测限和定量限分别为0.10和0.34 μM。该方法的精密度以重复性（日内分析n = 3×3）的相对标准偏差表示，铁（Ⅱ）和铁（Ⅲ）分别为2.03%和3.17%；以再现性（日间分析n = 5×3）的相对标准偏差表示，铁（Ⅱ）和铁（Ⅲ）分别为3.11%和4.55%。该方法的回收率以平均百分比（n = 3）表示，铁（Ⅱ）和铁（Ⅲ）分别在100.1 - 104.1%和98.08 - 102.7%范围内。然后该方法成功应用于饮用水中铁形态的痕量测定。
