Grafting polymer–protein bioconjugate to boron-doped diamond using aryl diazonium coupling agents

• Aryl layers from diazonium salts initiate photopolymerization of HEMA at BDD surface.
• BDD-PHEMA hybrids resist non-specific protein adsorption.
• BSA-activated BDD-PHEMA hybrids selectively recognize anti-BSA over anti-myoglobin.
• Aryl diazonium salts are versatile and trendy compounds for making bioactive BDD.

Highly boron doped diamond (BDD) surface was grafted with 4-benzoylphenyl (BP), a photopolymerization initiator group, to provide a platform for surface-confined radical photopolymerization of 2-hydroxyethyl methacrylate (HEMA). The PHEMA-modified BDD hybrid (BDD-PHEMA) resisted non-specific adsorption while the imidazole-functionalized PHEMA graft readily reacted with BSA to provide a bioactive BDD substrate. After incubation of BDD-PHEMA-BSA in anti-BSA and anti-myoglobin solution, it was found that BDD-PHEMA-BSA selectively retained anti-BSA. This work paves the way to fabrication of bioactive BDD layers through a simple process combining the surface chemistry of aryl diazonium salts and photopolymerization.

Figure optionsDownload as PowerPoint slide