A novel type of responsive double hydrophilic block copolymer-based multifunctional fluorescence chemosensor and its application in biological samples

Abstract

In this paper, a novel type of responsive double hydrophilic block copolymer (DHBC)-based multifunctional chemosensors to Al3+, Zn2+ and temperature was designed and prepared. The well-defined DHBCs with Al3+ and Zn2+-reactive thermosensitive block (copolymer fluorescence chemosensor), poly(ethylene oxide)-b-poly(N-isopropylacrylamide-co-SHMA)65(PEO113-b-P(NIPAM-co-SHMA)65, Mn=13.2kDa,Mw/Mn=1.09), were synthetized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The novel well water-soluble copolymer fluorescence chemosensor could selectively recognize Al3+ (blue fluorescence) and Zn2+ (green fluorescence) by the difference of the fluorescence color. Moreover, this copolymer fluorescence chemosensor has the ability to selective recognition Al3+ or Zn2+ in their mixed solution by controlling the fluorescence response time. The detection limit of 0.1g/L copolymer fluorescence chemosensor for the analysis of Al3+ and Zn2+ ions at 25°C were calculated to be ∼5.23 and ∼11.99ppb, respectively. PEO113-b-P(NIPAM-co-SHMA) can self-assemble into micelles with P(NIPAM-co-SHMA) block as core and well-solvated PEO block as coronas when heating to the lower critical solution temperature (LCST), and the detection limit of Al3+ and Zn2+ ions at 40°C can be decreased to ∼2.14 and ∼8.71ppb, respectively. Furthermore, the copolymer fluorescence chemosensor has been successfully applied to detect Al3+ and Zn2+ in biological samples.