Translated Title
Study of Di rect Fluorescence Quenching of Graphitic Carbon Nitride for the Detection of Iodine Ions
Translated Abstract
Iodine is one of essential trace elements .Deficiency of iodine and excess intake of iodine both can lead to thyroid diseases .T herefore ,it is of great significance to develop a highly sensitive and selective method for the detection of iodine ions . T raditional analytical methods for iodine ions are usually involved in complex sample pretreatment and precision instruments , w hich are unfavorable for in-situ rapid detection .Fluorescent methods have been attracted great attentions due to their high sen-sitivity ,high selectivity and easy operation.However ,the present probes for iodine ions usually need complex organic syntheses and iodine ions are detected by means of coordination with heavy metal ions ,w hich are unfavorable to promote the use of these methods .Fluorescent graphitic carbon nitride (g-C3 N4 ) nanomaterial has attracted more attention due to the advatages of low-cost ,easy preparation ,high quantum yield ,excellent photostability ,and low toxicity .Furthermore ,these nanomaterials can a-void complex synthesis for organic fluorophores or potential damage to environment for metal semiconductor quantum dots . T hese features make g-C3 N4 nanomaterial an emerging fluorescent probe for the detection of metal ions .Recently ,it w as repor- ted that Hg2+ ions could selectively and sensitively quench the fluorescence of g-C3 N4 quantum dots (QDs).T he addition of io-dine ions could abstract the bound Hg2+ ions to form HgI2 complexes and restored the fluorescence of g-C3 N4 QDs .T herefore , the fluorescent sensor for iodine ions could be developed .However ,heavy metal ions (Hg2+) are also involved in this method , w hich limits its application .In this work ,water-soluble g-C3N4 QDs with high fluorescence emission were prepared by using chemical oxidation of bulk g-C3 N4 in nitric acid and hydro-thermal treatment .T he maximal emission wavelength of g-C3 N4 QDs located at 368 nm and did not change with the excitation wavelength ,w hich indicates the size of g-C3 N4 QDs is relatively uni-form .T here was a strong absorption peak at around 220 nm for iodine ions ,w hich was overlapped with the fluorescent excitation spectrum of g-C3 N4 QDs .On addition of iodine ions ,the fluorescence of g-C3 N4 QDs was quenched due to the inner filter effect . T herefore ,a sensitive and selective fluorescent sensor for iodine ions was developed .Under the optimal conditions ,there was a linear relationship between the fluorescence quenching (Δ F) of g-C3 N4 QDs and the concentration (X ,μmol·L －1 ) of iodine i-ons over the range of 10～400 μmol·L －1 .T he linear equation is Δ F＝0. 325 79 X+6.039 05 (R2 ＝0.999 5).T he limit of de-tection is 5. 0 μmol·L －1 .T he detection of iodine ions can be completed by ＂mixing and testing＂ without the need of coordination with heavy metal ions .T hus ,this sensor is rapid ,environment-friendly ,simple and convenient .
Translated Keyword
Fluorescent sensor
Graphitic carbon nitride
Inner filter effect
Iodide ions
Access Number
WF:perioarticalgpxygpfx201907007
