- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A sequential and reversibility fluorescent pentapeptide probe for Cu(II) ions and hydrogen sulfide detections and its application in two different living cells imaging
摘要： In this study, we report a sequential and reversibility fluorescent probe (DP5) based on pentapeptide conjugated with dansyl groups using the solid phase peptide synthesis (SPPS) technology. DP5 showed immediate “turn off” response toward Cu2+ ions at an excitation wavelength of 330 nm with detection limits of 23.5 nM. The 2:1 binding ratio between DP5 and Cu2+ were confirmed using Job's plot method and fluorescence titration study, and DP5-Cu complex was observed with an association constant of 6.76 × 108 M?2. As designed, DP5-Cu complex as a promising analytical probe exhibited highly selective for H2S detection in aqueous solutions. The detection limit for H2S was obtained to be 17.2 nM, and lower than EPA and WHO guidelines. In addition, the reversibility and cyclicity were imparted to the DP5 during the detection of Cu2+ and H2S, and cycle effect is very good. Furthermore, DP5 displayed better biocompatibility and low biotoxicity, and sequential fluorescence “on-off-on” responses of DP5 to Cu2+ and H2S were successfully applied in two different living cells.
关键词： Cu2+ ions,Pentapeptide,Fluorescent probe,Cell imaging,Hydrogen sulfide,Aqueous solutions
更新于2025-11-21 11:08:12
-
Structural Dynamics of Dimethyl Sulfoxide Aqueous Solutions Investigated by Ultrafast Infrared Spectroscopy: Using Thiocyanate Anion as a Local Vibrational Probe
摘要： The microscopic structure of dimethyl sulfoxide (DMSO) aqueous solutions was investigated by FTIR spectroscopy and ultrafast IR spectroscopy. The structural dynamics of the binary mixtures were reflected by using thiocyanate anion (SCN-) as a local vibrational probe. FTIR spectra of SCN- anion showed the hydrogen bond networks of water are affected by the presence of DMSO molecules, and the peak position and bandwidth of SCN- anions are red-shifted and narrowed accordingly due to the weak hydration in the binary mixture. The vibrational lifetime of the SCN- anion showed almost linear enhancement with the increase of DMSO, which can be explained by the weak interaction between SCN- and the hydrophobic groups in DMSO molecule. However, the rotational dynamics of SCN- are slowing down significantly and showed a maximum response at XDMSO (mole fraction) of 0.35, which is mainly caused by the confinement of SCN- anions positioned in the vicinity of the complex structure formed between DMSO and water molecules. The concentration dependent rotational dynamics of water molecules and SCN- anions are having similar behavior, indicated that the complex structure can be formed between water and DMSO molecules due to the strong interaction. The result also demonstrates that the structural inhomogeneity in aqueous solution can be unraveled by monitoring the vibrational relaxation dynamics of SCN- anion serving as the local vibrational probe.
关键词： structural dynamics,thiocyanate anion,FTIR spectroscopy,Dimethyl sulfoxide,ultrafast IR spectroscopy,aqueous solutions,vibrational probe
更新于2025-09-10 09:29:36