Light-activated coupling of oligonucleotides to polymers

A method of coupling oligonucleotides to a polymer, comprising

• selectively irradiating first inactive moieties in a one or more first region of a polymer with light, while not irradiating second inactive moieties in a one or more second region of the polymer, to generate first active moieties in the one or more first region of the polymer;
• coupling the first active moieties to first oligonucleotides;
• irradiating the second inactive moieties in the one or more second region of the polymer with light to generate second active moieties in the one or more second region of the polymer;
• and
• coupling the second active moieties to second oligonucleotides, wherein
• one or both of the first inactive moieties and the second inactive moieties comprise a protecting group wherein the protecting group is selected from an o-nitrobenzyl having a structure selected from
• wherein R2 and R3 are each independently selected from —H and —O—CH3, and
• a benzopyrone having a structure
• wherein R4 is selected from —H, —O—CH3, and —N—(CH3)2, and R8 is selected from —H and —Br,
• Z comprises an alkane comprising one or more of —CH2—, (—CH2)m, and (—CH2—O—)n, wherein m and n are independently an integer from 0 to 50, and
• X is selected from —S and —N(H)—, and
• R1 is a linkage to a backbone of the polymer.