Pimsin Nipaporn, Keawprom Chayanee, Areerob Yonrapach, Limchoowong Nunticha, Sricharoen Phitchan, Nuengmatcha Prawit, Oh Won-Chun, Chanthai Saksit
Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University Khon Kaen 40002 Thailand
Department of Industrial Engineering, School of Engineering, King Mongkut's Institute of Technology Ladkrabang Bangkok 10520 Thailand.
RSC Adv. 2022 May 12;12(23):14356-14367. doi: 10.1039/d2ra01381a.
The goal of this work was to use the pyrolysis process to synthesize graphene quantum dots doped with garlic extract (as N,S-GQDs) and simultaneously co-doped with iodine (as I-GQDs). XPS, HR-TEM, FE-SEM/EDX, FT-IR, fluorescence, and UV-visible absorption spectroscopy were used to characterize the N,S,I-GQDs and analyze their morphological images. The quantum yield of N,S,I-GQDs was found to be 45%, greater than that of undoped GQDs (31%). When stimulated at 363 nm, the N,S,I-GQDs display a strong fluorescence intensity at a maximum wavelength of 454 nm. Using N,S,I-GQDs as a fluorescence quenching sensor for screening tests with various metal ions, it was discovered that they are extremely selective towards Fe over Fe and other ions. Thus, solution pH, concentration of N,S,I-GQDs, quantity of garlic extract, EDTA and AgNO concentration as masking agents, reaction duration under ultrasonic aid, and tolerable limit of Fe presence in the target analyte were all optimized for Fe detection. A highly sensitive detection of Fe was obtained using a linear curve with = 141.34 + 5.5855, = 0.9961, LOD = 0.11 mg L, and LOQ = 0.35 mg L. The method precision, given as RSDs, was determined to be satisfactory at 1.04% for intra-day analysis and 3.22% for inter-day analysis, respectively. As a result, the selective determination of trace amounts of Fe in real water samples using such labile multi-element doped GQDs in conjunction with garlic extract as a green chelating agent to maintain its enhanced sensitivity was successfully applied with good recoveries ranging from 89.16 to 121.45%.
这项工作的目标是利用热解过程合成掺杂大蒜提取物的石墨烯量子点（作为N，S-GQDs）并同时与碘共掺杂（作为I-GQDs）。采用X射线光电子能谱（XPS）、高分辨率透射电子显微镜（HR-TEM）、场发射扫描电子显微镜/能谱仪（FE-SEM/EDX）、傅里叶变换红外光谱（FT-IR）、荧光光谱和紫外可见吸收光谱对N，S，I-GQDs进行表征并分析其形态图像。发现N，S，I-GQDs的量子产率为45%，高于未掺杂的GQDs（31%）。当在363nm激发时，N，S，I-GQDs在最大波长454nm处显示出很强的荧光强度。将N，S，I-GQDs用作荧光猝灭传感器对各种金属离子进行筛选测试，发现它们对Fe比对Fe和其他离子具有极高的选择性。因此，针对Fe检测，对溶液pH值、N，S，I-GQDs浓度、大蒜提取物用量、作为掩蔽剂的乙二胺四乙酸（EDTA）和硝酸银（AgNO₃）浓度、超声辅助下的反应持续时间以及目标分析物中Fe的可耐受限度进行了优化。使用线性曲线y = 141.34 + 5.5855x（R² = 0.9961）获得了对Fe的高灵敏度检测，检测限（LOD）为0.11mg/L，定量限（LOQ）为0.35mg/L。以相对标准偏差（RSDs）表示的方法精密度在日内分析时为1.04%，日间分析时为3.22%，结果令人满意。因此，使用这种不稳定的多元素掺杂GQDs结合大蒜提取物作为绿色螯合剂以保持其增强的灵敏度，成功地应用于实际水样中痕量Fe的选择性测定，回收率良好，范围为89.16%至121.45%。
