(379a) Photopolymerizations and Their Application to Biodetection

Photopolymerization reactions have numerous distinct advantages over conventional polymerizations including the ability to control in time and space the occurrence of the polymerization reaction. Further, the kinetics of the reaction and the degree of polymerization depend significantly on the initiation conditions as well as the polymer formulation. Extremely high degrees of polymerization are achieved when dilute radicals polymerize highly functional monomer formulations that lead to crosslinked polymers.

Here, we demonstrate in several applications that these advantages of photopolymerizations, particularly radical-mediated photopolymerizations, enable facile detection of minute biological quantities in a process referred to as polymerization-based amplification. The ability to initiate photopolymerization in direct response to the specific and selective detection of biological moieties is shown to enable oligonucleotide and antigen detection in microarray format while also promoting facile, organelle specific immunofluorescent staining. In each of these applications, radical-mediated photopolymerization is used to enhance dramatically the detection limit and to improve the signal that results from a given target density. In particular, on the order of 1000 biotin-labeled oligonucleotides on a microarray surface are converted into a macroscopically visible, target-specific response. Further, a three order of magnitude reduction in primary antibody utilization is achieved in immunofluorescent staining techniques that employ polymerization-based amplification.