ﺳﻨﺘﺰ ﻧﻘﺎط ﮐﻮاﻧﺘﻮﻣﯽ ﮔﺮاﻓﻦ ﺗﯿﻮلدار و ﮐﺎرﺑﺮد آن در اﻧﺪازهﮔﯿﺮي ﯾﻮن ﺟﯿﻮه

Synthesis of Thiolated Graphene Quantum Dots and Their Application in the Measurement of Mercury Ions

در اﯾﻦ ﭘﺮوژه اﺑﺘﺪا ﻧﻘﺎط ﮐﻮاﻧﺘﻮﻣﯽ ﮔﺮاﻓﻦ ﺗﯿﻮلدار ﺳﻨﺘﺰ ﺷﺪ. ﺷﻨﺎﺳﺎﯾﯽ ﻣﺎده ﺳﻨﺘﺰ ﺷﺪه ﺑﺎ اﺳﺘﻔﺎده از ﻃﯿﻒﺳﻨﺠﯽ ﻣﺎدون ﻗﺮﻣﺰ ﺗﺒﺪﯾﻞ ﻓﻮرﯾﻪ اﻧﺠﺎم ﺷﺪ و ﻣﺸﺨﺺ ﺷﺪ ﮐﻪ ﻧﻘﺎط ﮐﻮاﻧﺘﻮﻣﯽ ﺑﺎ ﻣﻮﻓﻘﯿﺖ ﺳﻨﺘﺰ ﺷﺪه اﺳﺖ. در اداﻣﻪ ﻧﺘﺎﯾﺞ ﻣﯿﮑﺮوﺳﮑﻮپ اﻟﮑﺘﺮوﻧﯽ ﻋﺒﻮري ﻧﺸﺎن داد ﮐﻪ اﻧﺪازه ﻧﻘﺎط ﮐﻮاﻧﺘﻮﻣﯽ زﯾﺮ 50 ﻧﺎﻧﻮﻣﺘﺮ ﻣﯽﺑﺎﺷﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺗﯿﻮلدار ﺷﺪن ﻧﻘﺎط ﮐﻮاﻧﺘﻮﻣﯽ ﮔﺮاﻓﻦ ﺑﻪ وﺳﯿﻠﻪ ﺳﯿﺴﺘﺎﻣﯿﻦ اﻧﺠﺎم ﺷﺪ. ﻧﺘﺎﯾﺞ ﺑﻪ دﺳﺖ آﻣﺪه ﻧﺸﺎن داد ﺑﻪ ﮐﻤﮏ ﻧﻘﺎط ﮐﻮاﻧﺘﻮﻣﯽ ﮔﺮاﻓﻦ ﺗﯿﻮلدار، ﻣﻘﺎدﯾﺮ ﺑﺴﯿﺎر ﻧﺎﭼﯿﺰ ﺟﯿﻮه ﻗﺎﺑﻞ ﺷﻨﺎﺳﺎﯾﯽ ﻣﯽﺑﺎﺷﺪ. ﺑﺮاي اﯾﻦ ﻣﻨﻈﻮر، ﻓﺮاﯾﻨﺪ ﻓﺮوﻧﺸﺎﻧﯽ ﻧﻮرﺗﺎﺑﯽ ﻧﻘﺎط ﮐﻮاﻧﺘﻮﻣﯽ ﮔﺮاﻓﻦ ﺗﯿﻮلدار ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﺣﺪ ﺗﺸﺨﯿﺺ روش µM 0/16 و ﻣﺤﺪوده ﺧﻄﯽ ﻏﻠﻈﺖ µM 0/5 ﺗﺎ mM 1/0 ﺗﻌﯿﯿﻦ ﺷﺪ. ﺳﺮاﻧﺠﺎم ﮐﺎرﺑﺮد اﯾﻦ ﻧﺎﻧﻮ ذرات ﺑﺮاي اﻧﺪازهﮔﯿﺮي ﺟﯿﻮه در ﻧﻤﻮﻧﻪﻫﺎي ﺣﻘﯿﻘﯽ و ﮔﺰﯾﻨﺶﭘﺬﯾﺮي روش ﺑﺎ ﻧﺘﺎﯾﺞ رﺿﺎﯾﺖﺑﺨﺸﯽ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار ﮔﺮﻓﺖ.

In this work, at first thiolated graphene quantum dots (tio-GQDs) was synthesized. Characterization of the synthesized compound was carried out by the use of infrared spectroscopy. The obtained results confirmed that the tio-GQDs were successfully synthesized. The size of these quantum dots was investigated by TEM. On the base of achieved images, the average dimeters of nanoparticles were estimated about 50 nm. The oxidized GQDs were thiol functionalized with cysteamine. In the following the prepared nanoparticles were applied for the determination of trace amount of mercury. To this end, the fluorescent quenching process of tio-GQDs was investigated. Fluorescent quenching process was very fast that was an important advantage of this nanosensor. The limit of detection was obtained 0.160 μM and linear concentration rang 0.5 µM to 1 mM. Interference effects of other ions on mercury determination by thio-GQDs were studied in the presence of other species. The usage of tio-GQDs for determination of mercury is an easy, effective, fast, inexpensive, low toxicity and environmentally friendly method. Finally, the synthesized thiolated graphene quantum dots were applied for the determination of mercury in the real samples and selectivity with satisfactory results.