It is particularly important to monitor Cr(Ⅵ)for its high toxicity.In this paper,a novel,simple,low-cost and"on-off-on"fluorescence sensor of carbon dots doped with nitrogen and phosphorus(N,P-CDs)was devel...It is particularly important to monitor Cr(Ⅵ)for its high toxicity.In this paper,a novel,simple,low-cost and"on-off-on"fluorescence sensor of carbon dots doped with nitrogen and phosphorus(N,P-CDs)was developed via one-step hydrothermal method for highly sensitive and good selective detection of Cr(Ⅵ)and ascorbic acid(AA).The prepared N,P-CDs exhibited the ability for detection of Cr(Ⅵ)based on the inner filter effect(IFE)and static quenching.Under optimized conditions,the fluorescence quenching efficiency of N,P-CDs showed a good linear correlation with Cr(Ⅵ)concentration ranged from0.68 to 87.38μmol/L(R^(2)=0.9946).The limit of detection(LOD)was 0.18μmol/L,which was acceptable compared with the maximum Cr(Ⅵ)concentration of 0.96μmol/L in drinking water prescribed by WHO.In addition,the N,P-CDs/Cr(Ⅵ)hybrid were also used as"turn-on"fluorescent transducers for detecting AA with a wide linear region ranged from 0.02 to933.33μmol/L(R^(2)=0.9972).Furthermore,the N,P-CDs fluorescence sensor had admissible applicability for Cr(Ⅵ)and AA detection in actual water samples with acceptable recovery rate,indicating that the fluorescence sensor had great application potential in environmental monitoring and food field.展开更多
目的研究新型芳基异丙酸类化合物2-[4-(3-氧代丁基)苯基]丙酸(OPPA)与牛血清白蛋白(BSA)的相互作用。方法利用瞬态/稳态荧光光谱法和紫外光谱法,测算结合常数、结合位点数、热力学参数和分子的结合距离。结果在25℃下,反应平衡常数为3.9...目的研究新型芳基异丙酸类化合物2-[4-(3-氧代丁基)苯基]丙酸(OPPA)与牛血清白蛋白(BSA)的相互作用。方法利用瞬态/稳态荧光光谱法和紫外光谱法,测算结合常数、结合位点数、热力学参数和分子的结合距离。结果在25℃下,反应平衡常数为3.9×104L·mol-1,结合位点数为0.8;焓变为-16.29 k J·mol-1,熵变为205.04 J·mol-1·K-1,吉布斯自由能为-26.21 k J·mol-1;OPPA与BSA分子中色氨酸的最近距离为3.26 nm。结论 OPPA与BSA的相互作用为动态猝灭和静态猝灭的协同机理,OPPA与BSA的相互作用力主要是疏水相互作用力和静电作用力相互作用。展开更多
Photoinduced electron transfer reaction between the excited state ruthenium (II) polypyridyl complexes and quinones has been investigated in cetyltrimethylammonium bromide using luminescent quenching techniques. The c...Photoinduced electron transfer reaction between the excited state ruthenium (II) polypyridyl complexes and quinones has been investigated in cetyltrimethylammonium bromide using luminescent quenching techniques. The complexes have the absorption and emission maximum in the range 452 - 468 nm and 594 - 617 nm respectively. The static nature of quenching is confirmed from the ground state absorption studies. The association constants for the complexes with quinones are calculated from the Benesi-Hildebrand plots using absorption spectral data. The value of quenching rate constant (kq) is highly sensitive to the nature of the ligand and the quencher, the medium, structure and size of the quenchers. Compared to the aqueous medium, the electron transfer rate is altered in CTAB medium. The oxidative nature of the quenching is confirmed by the formation of Ru3+ ion and quinone anion radical.展开更多
基金financially sponsored by the National Natural Science Foundation of China(21777131,22176154)Science and Technology Department Foundation of Sichuan Province(22ZDYF1945)
文摘It is particularly important to monitor Cr(Ⅵ)for its high toxicity.In this paper,a novel,simple,low-cost and"on-off-on"fluorescence sensor of carbon dots doped with nitrogen and phosphorus(N,P-CDs)was developed via one-step hydrothermal method for highly sensitive and good selective detection of Cr(Ⅵ)and ascorbic acid(AA).The prepared N,P-CDs exhibited the ability for detection of Cr(Ⅵ)based on the inner filter effect(IFE)and static quenching.Under optimized conditions,the fluorescence quenching efficiency of N,P-CDs showed a good linear correlation with Cr(Ⅵ)concentration ranged from0.68 to 87.38μmol/L(R^(2)=0.9946).The limit of detection(LOD)was 0.18μmol/L,which was acceptable compared with the maximum Cr(Ⅵ)concentration of 0.96μmol/L in drinking water prescribed by WHO.In addition,the N,P-CDs/Cr(Ⅵ)hybrid were also used as"turn-on"fluorescent transducers for detecting AA with a wide linear region ranged from 0.02 to933.33μmol/L(R^(2)=0.9972).Furthermore,the N,P-CDs fluorescence sensor had admissible applicability for Cr(Ⅵ)and AA detection in actual water samples with acceptable recovery rate,indicating that the fluorescence sensor had great application potential in environmental monitoring and food field.
文摘目的研究新型芳基异丙酸类化合物2-[4-(3-氧代丁基)苯基]丙酸(OPPA)与牛血清白蛋白(BSA)的相互作用。方法利用瞬态/稳态荧光光谱法和紫外光谱法,测算结合常数、结合位点数、热力学参数和分子的结合距离。结果在25℃下,反应平衡常数为3.9×104L·mol-1,结合位点数为0.8;焓变为-16.29 k J·mol-1,熵变为205.04 J·mol-1·K-1,吉布斯自由能为-26.21 k J·mol-1;OPPA与BSA分子中色氨酸的最近距离为3.26 nm。结论 OPPA与BSA的相互作用为动态猝灭和静态猝灭的协同机理,OPPA与BSA的相互作用力主要是疏水相互作用力和静电作用力相互作用。
文摘Photoinduced electron transfer reaction between the excited state ruthenium (II) polypyridyl complexes and quinones has been investigated in cetyltrimethylammonium bromide using luminescent quenching techniques. The complexes have the absorption and emission maximum in the range 452 - 468 nm and 594 - 617 nm respectively. The static nature of quenching is confirmed from the ground state absorption studies. The association constants for the complexes with quinones are calculated from the Benesi-Hildebrand plots using absorption spectral data. The value of quenching rate constant (kq) is highly sensitive to the nature of the ligand and the quencher, the medium, structure and size of the quenchers. Compared to the aqueous medium, the electron transfer rate is altered in CTAB medium. The oxidative nature of the quenching is confirmed by the formation of Ru3+ ion and quinone anion radical.
