We have prepared bifunctional linkers containing clickable functional groups that enable preparation of protein-DNA conjugates through binding onto tyrosine residues. Mild conjugation strategy was demonstrated using two proteins, streptavidin(STV) and myoglobin (Mb) and it resulted in conjugates with preserved functionality of both the proteins and DNA strands. Furthermore, we show that protein-DNA conjugates can be successfully immobilized onto solid surface containing complementary DNA strands and the enzymatic activity of Mb-DNA conjugates is even higher than that of corresponding conjugates prepared through Lys binding.

A photochemical approach based on nitrile imine-mediated tetrazole-ene cycloaddition is introduced to functionalize gold nanorods with biomolecules. For this purpose, a bifunctional, photoreactive linker containing thioctic acid as the Au anchoring group and a tetrazole moiety for the light-induced reaction with maleimide-capped DNA was prepared. The tetrazole-based reaction on the nanoparticles' surface results in a fluorescent pyrazoline product allowing for the spectroscopic monitoring of the reaction. This first example of nitrile imine-mediated tetrazole-ene cycloaddition (NITEC)-mediated biofunctionalization of Au nanorods paves the way for the attachment of sensitive biomolecules, such as antibodies and other proteins, under mild conditions and expands the toolbox for the tailoring of nanomaterials.

A photocaged diene is introduced at the 5′-end of oligonucleotides using the H-phosphonate approach and subsequently employed for the light-induced conjugation to a protein and the spatially controlled immobilization onto surfaces.