Biotin-Initiated Poly(Oxazoline)s

Biotinylated hydrophilic polymers are used in a plethora of chemical and biochemical assays due to the exceptional affinity of biotin for (strept)avidin. Here we report a facile method for the installation of biotin at the end of poly(oxazoline)s (P(Ox)) using an electrophilic biotin initiator. While this method is applicable to many different oxazoline monomers, we focus on biotin-poly(2-methyl-2-oxazoline) as it is a desirable alternative to poly(ethylene glycol) (PEG), which has rising immunogenicity concerns. A further advantage of POx over PEG is the high degree of chemical flexibility that can be imparted, which we showcase through the preparation of varied molecular weight, amphiphilic, and bifunctional POxs. Furthermore, we demonstrate the high efficacy of these biotin polymers through a series of common biochemical assays that frequently utilize the biotin-streptavidin pair.