A chemosensing ensemble for the detection of cysteine based on the inner filter effect using a rhodamine B spirolactam.
A fluorescent chemosensing ensemble for the detection of cysteine is designed based on the fluorescence inner filter effect. The method employs the coordination of Cu(2+) ion with salicylaldehyde rhodamine B hydrazone (I), a colorless and non-fluorescent rhodamine B spirolactam derivative to form I-Cu(II), a pink color but weakly fluorescent complex. When rhodamine B was introduced to the I-Cu(II) complex solution, the fluorescence signal of rhodamine B is dramatically decreased because of the fluorescence inner filter effect (IFE). Upon adding cysteine to the above solution, it can complex preferentially to Cu(2+) compared to I, and the I-Cu(II) complex dissociates, which thus decreases the fluorescence IFE of the solution, and in turn leading to the fluorescence increase of the chemosensing system. Based on the above mechanism, a fluorescent chemosensing ensemble for cysteine is developed. The fluorescence increase is linearly with cysteine concentration up to 10.0 mu mol L(-1), with a detection limit of 1.4 x 10(-7) mol L(-1) (3sigma). The optimal conditions of the proposed method were studied and the selectivity of the proposed method was investigated in this paper.
Yang
Xiao-Feng
XF
Department of Chemistry, Northwest University, Xi'an, China. xfyang@mail.china.com
Liu
Ping
P
Wang
Liping
L
Zhao
Minglei
M
D015374:Biosensing Techniques; D019327:Copper Sulfate / Q000737:chemistry*; D003545:Cysteine / Q000032:analysis* / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D012235:Rhodamines / Q000138:chemical synthesis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
D005456:Fluorescent Dyes; D012235:Rhodamines; D003545:Cysteine; D019327:Copper Sulfate