Highly stable and polymerizable δ-valerolactones bearing oligo(ethylene glycol) methyl ether functionalities are facilely prepared by alkylphosphine catalyzed thiol–ene addition with an exocyclic α,β-unsaturated δ-valerolactone. The functionalized lactones undergo efficient ring-opening polymerization (ROP) to afford well defined PEG-like polyesters. Kinetic studies revealed that the ROP, catalyzed by diphenyl phosphate at ambient temperature, shows living nature. The results of cell viability assays indicate that the resultant polyesters are fully biocompatible. In vitro tests on protein adsorption and cell adhesion demonstrate that the antifouling capability of these polyesters is comparable to that of PEG. The strategy for facile preparation of stable and polymerizable lactones bearing functional substituents reported here provides a versatile platform for the development of polyester-based new biocompatible and biodegradable polymeric materials for biomedical applications.

A rationally designed small-molecule fluorogenic probe for nitric oxide (NO) detection based on a new switching mechanism has been developed. Attaching a NO-responsive dihydropyridine pendant group to a fluorophore led to a probe that displays a very high sensitivity to NO concentrations down to the low nM range and a very high specificity to NO while being insensitive to other oxidative oxygen/nitrogen species that often interfere with the sensing of NO.

A rationally designed small-molecule fluorogenic probe for nitric oxide (NO) detection based on a new switching mechanism has been developed. Attaching a NO-responsive dihydropyridine pendant group to a fluorophore led to a probe that displays a very high sensitivity to NO concentrations down to the low nM range and a very high specificity to NO while being insensitive to other oxidative oxygen/nitrogen species that often interfere with the sensing of NO.