A dual thermoresponsive and antifouling zwitterionic microgel with pH triggered fluorescent "on -off" core

S.L. Banerjee, P. Saha, R. Ganguly, K. Bhattacharya, U. Kalita, A. Pich, N.K. Singha*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

8 Citations (Web of Science)


A unique, tailor-made, zwitterionic, dual thermoresponsive and fluorescent microgel probe was synthesized via Reversible Addition Fragmentation chain-Transfer (RAFT) polymerization. Microgels were pre pared via oil in water (o/w) emulsion polymerization where poly(carboxybetaine) (PCB) acted as a macro-RAFT reagent as well as an emulsifier. The presence of poly(N-vinylcaprolactam) (PNVCL) in the microgel system imparts the thermoresponsiveness to the system and the presence of a rhodamine derivative as fluorophore makes it responsive to pH change of the system by showing a fluorescence emission at 580 nm (reddish orange color). The dual thermoresponsiveness [i.e. the presence of upper critical solution temperature (UCST @ 12 degrees C) as well as lower critical solution temperature (LCST @ 33 degrees C)] of the microgels was studied via UV-visible spectroscopy (UV-vis) and temperature responsive dynamic light scattering (DLS) analyses. Presence of the PCB in the corona-crosslinked microgel, played a vital role in the formation of self-assembled structure as well as in protein immobilization (antifouling activity). Antifouling property was studied using UV-vis spectroscopy where bovine serum albumin (BSA) was taken as a model protein. The presence of the pH-responsive fluorescence, thermoresponsiveness as well as antifouling properties makes this zwitterionic microgel system a potential a potential candidate for medical diagnostics and for drug delivery vehicles. (c) 2020 Elsevier Inc. All rights reserved.
Original languageEnglish
Pages (from-to)110-126
Number of pages17
JournalJournal of Colloid and Interface Science
Publication statusPublished - 1 May 2021


  • antifouling
  • dual thermoresponsiveness
  • fluorescence
  • lsct
  • microgel
  • ucst
  • zwitterion
  • Antifouling
  • UCST
  • Fluorescence
  • Zwitterion
  • Dual thermoresponsiveness
  • Microgel
  • LSCT

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