A composition comprising: a substrate comprising a functionalized surface; and a quaternary phosphonium compound bound to the functionalized surface, wherein the quaternary phosphonium compound has a radical of formula I: wherein X 1, X 2, X 3, and X 4 are independently non-existent or independently selected from O, S, NR 5, =N-, PR 6, and =P-; and wherein R 1, R 2, R 3, R 4, R 5, and R 6 are independently selected from the group consisting of hydrogen, alkyls, substituted alkyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, alkenyl, substituted cycloalkenyl, alkynyl, substituted alkynyl, haloalkyl, hydroxyalkyl, alkoxy, alkoxyalkyl, heteroalkyl, haloalkoxy, aryl, substituted aryl, aryloxy, aralkyloxy, heteroaryl, substituted heteroaryl, heterocycle, substituted heterocycle, amino, alkylamino, dialkylamino, hydroxyalkylamino, (amino)alkyl, (alkylamino)alkyl, (dialkylamino)alkyl, (cyano)alkyl), carboxamido, (carboxamido)alkyl, methacrylate, methacrylamide, sulfonamide, alkylcarbonyl, arylcarbonyl, alkylsulfonyl, arylsulfonyl, mercaptoalkyl, carboxy, carboxyalkyl, ureido, guanidine, (heterocyclo)alkyl, (heteroaryl)alkyl, wherein the functionalized surface is either natively functionalized or functionalized with a functionalizing agent covalently bound thereto, further comprising a linker, having a proximal end and a distal end, wherein the linker is covalently bound on its proximal end to the natively functionalized surface or to the functionalizing agent, and wherein the linker is covalently bound on its distal end to the quaternary phosphonium compound, wherein the linker has the structure: wherein n1 is between 1 and 100 and R' is independently a hydrogen, or a quaternary phosphonium compound. a substrate comprising a functionalized surface; and a quaternary phosphonium compound bound to the functionalized surface, wherein the quaternary phosphonium compound has a radical of formula I: wherein X 1, X 2, X 3, and X 4 are independently non-existent or independently selected from O, S, NR 5, =N-, PR 6, and =P-; and wherein R 1, R 2, R 3, R 4, R 5, and R 6 are independently selected from the group consisting of hydrogen, alkyls, substituted alkyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, alkenyl, substituted cycloalkenyl, alkynyl, substituted alkynyl, haloalkyl, hydroxyalkyl, alkoxy, alkoxyalkyl, heteroalkyl, haloalkoxy, aryl, substituted aryl, aryloxy, aralkyloxy, heteroaryl, substituted heteroaryl, heterocycle, substituted heterocycle, amino, alkylamino, dialkylamino, hydroxyalkylamino, (amino)alkyl, (alkylamino)alkyl, (dialkylamino)alkyl, (cyano)alkyl), carboxamido, (carboxamido)alkyl, methacrylate, methacrylamide, sulfonamide, alkylcarbonyl, arylcarbonyl, alkylsulfonyl, arylsulfonyl, mercaptoalkyl, carboxy, carboxyalkyl, ureido, guanidine, (heterocyclo)alkyl, (heteroaryl)alkyl, wherein the functionalized surface is either natively functionalized or functionalized with a functionalizing agent covalently bound thereto, further comprising a linker, having a proximal end and a distal end, wherein the linker is covalently bound on its proximal end to the natively functionalized surface or to the functionalizing agent, and wherein the linker is covalently bound on its distal end to the quaternary phosphonium compound, wherein the linker has the structure: wherein n1 is between 1 and 100 and R' is independently a hydrogen, or a quaternary phosphonium compound. wherein X 1, X 2, X 3, and X 4 are independently non-existent or independently selected from O, S, NR 5, =N-, PR 6, and =P-; and wherein R 1, R 2, R 3, R 4, R 5, and R 6 are independently selected from the group consisting of hydrogen, alkyls, substituted alkyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, alkenyl, substituted cycloalkenyl, alkynyl, substituted alkynyl, haloalkyl, hydroxyalkyl, alkoxy, alkoxyalkyl, heteroalkyl, haloalkoxy, aryl, substituted aryl, aryloxy, aralkyloxy, heteroaryl, substituted heteroaryl, heterocycle, substituted heterocycle, amino, alkylamino, dialkylamino, hydroxyalkylamino, (amino)alkyl, (alkylamino)alkyl, (dialkylamino)alkyl, (cyano)alkyl), carboxamido, (carboxamido)alkyl, methacrylate, methacrylamide, sulfonamide, alkylcarbonyl, arylcarbonyl, alkylsulfonyl, arylsulfonyl, mercaptoalkyl, carboxy, carboxyalkyl, ureido, guanidine, (heterocyclo)alkyl, (heteroaryl)alkyl, wherein the functionalized surface is either natively functionalized or functionalized with a functionalizing agent covalently bound thereto, further comprising a linker, having a proximal end and a distal end, wherein the linker is covalently bound on its proximal end to the natively functionalized surface or to the functionalizing agent, and wherein the linker is covalently bound on its distal end to the quaternary phosphonium compound, wherein the linker has the structure: wherein n1 is between 1 and 100 and R' is independently a hydrogen, or a quaternary phosphonium compound.