Design of synthetic peptide-based fluorescence probes for turn-on detection of hyaluronan

Herein, we designed and examined a series of fluorescent peptide-based probes for turn-on detection of hyaluronan (HA), a member of the glycosaminoglycan family. We utilized two kinds of synthetic HA-binding peptides as the binding unit for HA, and each peptide was coupled with three kinds of environment-sensitive fluorophores as the signaling unit. From the examination of the peptides, fluorophores, and the position and number of fluorophore modification, we found that X7 peptide (RYPISRPRKR) labelled with an aggregation-induced emission (AIE) fluorogen, tetraphenylethene (TPE), at the N-terminal (named TPE-X7) did function as a light-up probe for HA. The response of TPE-X7 was highly selective to higher molecular weight HA in comparison with lower ones, having the possible potential for the analysis of HA size. TPE-X7 was also applicable to the quantification of HA in synovial fluids.