Polymer brushes for immobilizing molecules to a surface and having water-soluble or water-dispersible segments therein and probes bonded thereto

A sensor for detecting a biological molecule in an aqueous sample comprising:

• a substrate having a surface;
• and
• a plurality of polymer chains bound to said surface, each of said plurality of polymer chains comprising a water-soluble or water-dispersible segment and at least one probe bonded to said water-soluble or water-dispersible segment, the probe being selective for the biological molecule,
• wherein said polymer chains are synthesized according to a process comprising:
• (i) bonding an iniferter initiator to said surface at one or more points to form a derivatized surface, said iniferter initiator comprising an initiator-control agent adduct having the formula:
• 21
• wherein C is a moiety on the surface of the substrate;
• L is a linker group capable of bonding to at least one C moiety;
• q, r and t are independently 0 or 1, provided the sum of q+r+t is at least 1;
• Y is a residue capable of initiating free radical polymerization upon homolytic cleavage of the Y—S bond;
• S is sulfur;
• and, G is a nitrogen or an oxygen heteroatom;
• (ii) contacting said derivatized surface with a composition comprising a water-soluble or water-dispersible free radically polymerizable monomer mixture, the mixture containing an acrylamide-based monomer and at least 1 other monomer, and an unbound iniferter initiator under reaction conditions to form bound and unbound polymer chains comprising functionalized sites on the polymer chain, the functionalized sites being formed in their active state for reaction with the probe molecule;
• (iii) separating unbound polymer;
• and
• (iv) bonding probes to the bound polymer chains through the active functionalized sites.

A method of preparing a sensor for detecting a biological molecule in an aqueous sample, the method comprising:

• bonding an iniferter initiator to a substrate surface at one or more points to form a derivatized surface, said iniferter initiator comprising an initiator-control agent adduct having the formula:
• 25
• wherein C is a moiety on the surface of the substrate;
• L is a linker group capable of bonding to at least one C moiety;
• q, r and t are independently 0 or 1, provided the sum of q+r+t is at least 1;
• Y is a residue capable of initiating free radical polymerization upon homolytic cleavage of the Y—S bond;
• S is sulfur;
• and, G is a nitrogen or an oxygen heteroatom;
• contacting said derivatized surface with a composition comprising a water-soluble or water-dispersible free radically polymerizable monomer mixture, the mixture containing an acrylamide-based monomer and at least 1 other monomer, under reaction conditions to form bound polymer chains comprising a water-dispersible segment having a weight average molecular weight of at least about 1000 and one or more functionalized sites thereon, the functionalized site(s) being formed in its(their) active state for reaction with a probe selective for the biological molecule;
• separating unbound polymer;
• and
• bonding the probe to the bound polymer chains through the active functionalized sites.