title: Complete suppression of the fluorophore fluorescence by combined effect of multiple fluorescence quenching groups: A fluorescent sensor for Cu²⁺ with zero background signals.
abstract: The reaction-based fluorescent sensors have attracted increasing attention in the past decades. However, the application of these sensors for accurate sensing was significantly retarded by the background fluorescence from the sensors themselves. In this work, we demonstrated a novel strategy that the background fluorescence of the sensor could be completely eliminated by the combined effect of multiple fluorescence quenching groups. Based on this new strategy, as proof-of-principle study, a fluorescent sensor (CuFS) for Cu(2+) was judiciously developed. In CuFS, three types of fluorescence quenching groups were directly tethered to a commonly used coumarin fluorophore. The fluorescence of coumarin fluorophore in CuFS was completely suppressed by the combined effect of these fluorescence quenching groups. Upon treatment with 22 μM Cu(2+), sensor CuFS achieved a dramatic fluorescence enhancement (fluorescence intensity enhanced up to 811-fold) centered at 469 nm. The detection limits was determined to be 12.3 nM. The fluorescence intensity enhancement also showed a good linearity with the Cu(2+) concentration in the range of 12.3 nM to 2 μM. By fabricating test strips, sensor CuFS can be utilized as a simple tool to detect Cu(2+) in water samples. Furthermore, the fluorescent sensor was successfully applied in detecting different concentration of Cu(2+) in living cells.
authors.affiliation: Scientific Research Academy & School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China. Electronic address: longlingliang@163.com.
authors.forename: Lingliang
authors.initials: L
authors.lastname: Long
authors.affiliation: Scientific Research Academy & School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Scientific Research Academy & School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China. Electronic address: ahg5@ujs.edu.cn.
authors.forename: Aihua
authors.initials: A
authors.lastname: Gong
authors.affiliation: Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui Province Key Laboratory of R&D of Traditional Chinese Medicine, Anhui University of Traditional Chinese Medicine, Hefei, Anhui 230038, PR China.
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Hu
authors.affiliation: Scientific Research Academy & School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China. Electronic address: Chizhang@ujs.edu.cn.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy; D045744:Cell Line, Tumor; D003300:Copper / Q000032:analysis*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066244:Proton Magnetic Resonance Spectroscopy; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D005456:Fluorescent Dyes; D003300:Copper
keywords: Background fluorescence; Copper; Dyes/Pigments; Fluorescence; Fluorescent sensor