Electrochemical detection systems and components thereof

A system comprising a polymer, wherein the polymer includes subunits of Formula I:

• wherein:
• R1 in each instance is independently H, alkyl, cycloalkyl, aryl, heterocycle, heteroaryl, or a combination thereof;
• R2 in each instance is independently N or O;
• R3 in each instance is independently:
• H;
• alkyl, cycloalkyl, aryl, heterocycle, heteroaryl, or a combination thereof;
• or a nitrogen protecting group when R2 is N;
• or
• absent when R2 is O;
• R4 in each instance is a spacer arm;
• R5 in each instance is Formula II or Formula III:
• R6, R7, and R8 in each instance are independently H;
• alkyl, cycloalkyl, aryl, heterocycle, heteroaryl, or a combination thereof;
• a nitrogen protecting group;
• a tethered polypeptide;
• a tethered redox mediator;
• a linking arm;
• or a tethered subunit of Formula I, with the proviso that at least one of R6, R7, and R8 may be absent;
• and
• n in each instance is independently a positive integer.