pH-Dependent Optical Properties of a Poly(phenylene ethynylene) Conjugated Polyampholyte

被引：11

作者：

Ji, Eunkyung ^{[1
]}

Whitten, David G. ^{[2
,3
]}

Schanze, Kirk S. ^{[1
]}

机构：

[1] Univ Florida, Dept Chem, Gainesville, FL 32611 USA

[2] Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA

[3] Univ New Mexico, Ctr Biomed Engn, Albuquerque, NM 87131 USA

来源：

LANGMUIR | 2011年 / 27卷 / 05期

关键词：

POLYELECTROLYTES; POLYMERS; DERIVATIVES; ACID;

D O I：

10.1021/la104586t

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

A poly(phenylene ethynylene) conjugated polymer (PPE-NMe3+-COO-) containing tetraalkylammonium groups and carboxylate groups has been synthesized by Sonogashira coupling. Due to the presence of the strong cationic and weak anionic pendant units, the polymer undergoes a pH-induced transition from cationic polyelectrolyte to polyampholyte due to deprotonation of the carboxylic acid units in basic solution. Studies of the pH dependence of the polymers' optical properties reveal changes in absorption oscillator strength and fluorescence quantum efficiency that are triggered by the transition from cationic polyelectrolyte to polyampholyte nature. Stern-Volmer fluorescence quenching of PPE-NMe3+-COO- with a negatively charged quencher 1,4,5,8-naphthalenediimide-N,N-bis(methylsulfonate) (NDS) shows that the polymer fluorescence quenching is amplified at low pH where the polymer is a polycation, whereas the quenching efficiency is considerably less at high pH.

引用

页码：1565 / 1568

页数：4

共 23 条

[1] Highly sensitive biological and chemical sensors based on reversible fluorescence quenching in a conjugated polymer [J].