A Highly Selective and Sensitive Fluorescent Turn-Off Probe for Cu2+ Based on a Guanidine Derivative

Fei Ye; Qiong Chai; Xiao-Min Liang; Ming-Qiang Li; Zhi-Qiang Wang; Ying Fu

doi:10.3390/molecules22101741

A Highly Selective and Sensitive Fluorescent Turn-Off Probe for Cu²⁺ Based on a Guanidine Derivative

Molecules. 2017 Oct 16;22(10):1741. doi: 10.3390/molecules22101741.

Authors

Fei Ye¹, Qiong Chai², Xiao-Min Liang³, Ming-Qiang Li⁴, Zhi-Qiang Wang⁵, Ying Fu⁶

Affiliations

¹ Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, China. yefei@neau.edu.cn.
² Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, China. chaiqiong01@163.com.
³ Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, China. abcliangxiaomin@163.com.
⁴ Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, China. mqli@neau.edu.cn.
⁵ Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, China. wzq19910101@163.com.
⁶ Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, China. fuying@neau.edu.cn.

Abstract

A new highly selective and sensitive fluorescent probe for Cu²⁺, N-n-butyl-4-(1'-cyclooctene-1',3',6'-triazole)-1,8-naphthalimide (L), was synthesized and evaluated. The structure of compound L was characterized via IR, ¹H-NMR, ¹³C-NMR and HRMS. The fluorescent probe was quenched by Cu²⁺ with a 1:1 binding ratio and behaved as a "turn-off" sensor. An efficient and sensitive spectrofluorometric method was developed for detecting and estimating trace levels of Cu²⁺ in EtOH/H₂O. The ligand exhibited excitation and emission maxima at 447 and 518 nm, respectively. The equilibrium binding constant of the ligand with Cu²⁺ was 1.57 × 10⁴ M^-1, as calculated using the Stern.

Keywords: copper ion; fluorescence; guanidine; naphthalimide; octatomic ring.

MeSH terms

Copper / chemistry*
Fluorescent Dyes / chemistry*
Guanidine / chemistry*
Naphthalimides / chemistry*
Proton Magnetic Resonance Spectroscopy

Substances

Fluorescent Dyes
Naphthalimides
Copper
Guanidine