Multifunctional PHPMA-Derived Polymer for Ratiometric pH Sensing, Fluorescence Imaging, and Magnetic Resonance Imaging

Fengyu Su, Shubhangi Agarwal, Tingting Pan, Yuan Qiao, Liqiang Zhang, Zhengwei Shi, Xiangxing Kong, Kevin Day, Meiwan Chen, Deirdre Meldrum, Vikram Kodibagkar, Yanqing Tian

Research output: Contribution to journalArticlepeer-review

47 Scopus citations


In this paper, we report synthesis and characterization of a novel multimodality (MRI/fluorescence) probe for pH sensing and imaging. A multifunctional polymer was derived from poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA) and integrated with a naphthalimide-based-ratiometric fluorescence probe and a gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid complex (Gd-DOTA complex). The polymer was characterized using UV-vis absorption spectrophotometry, fluorescence spectrofluorophotometry, magnetic resonance imaging (MRI), and confocal microscopy for optical and MRI-based pH sensing and cellular imaging. In vitro labeling of macrophage J774 and esophageal CP-A cell lines shows the polymer's ability to be internalized in the cells. The transverse relaxation time (T2) of the polymer was observed to be pH-dependent, whereas the spin-lattice relaxation time (T1) was not. The pH probe in the polymer shows a strong fluorescence-based ratiometric pH response with emission window changes, exhibiting blue emission under acidic conditions and green emission under basic conditions, respectively. This study provides new materials with multimodalities for pH sensing and imaging.

Original languageEnglish (US)
Pages (from-to)1556-1565
Number of pages10
JournalACS Applied Materials and Interfaces
Issue number2
StatePublished - Jan 17 2018


  • MRI
  • dual-modality
  • fluorescence imaging
  • pH sensor
  • polymer
  • ratiometric sensor

ASJC Scopus subject areas

  • General Materials Science


Dive into the research topics of 'Multifunctional PHPMA-Derived Polymer for Ratiometric pH Sensing, Fluorescence Imaging, and Magnetic Resonance Imaging'. Together they form a unique fingerprint.

Cite this