Conjugates of biomolecules to nanoparticles

A method for preparing a population of polymerase-nanoparticle conjugates which comprise a polymerase linked to a nanoparticle, where the polymerase includes a His-tag at the N-terminal end, and where the polymerase is linked to the nanoparticle via a His-tag mediated attachment, thereby forming a polymerase-nanoparticle conjugate, and where the conjugate has polymerase activity, wherein the polymerase-nanoparticle conjugate is prepared by:

• a) producing a polymerase including a His-tag, and
• b) contacting the polymerase with a nanoparticle and a quantity of an accessory compound under conditions where the polymerase becomes linked to the nanoparticle via a His-tag mediated attachment, thereby forming a a population of polymerase-nanoparticle conjugates with an average of about 0.5 to 1.5 polymerases per nanoparticle, wherein the accessory compound is selected from a group consisting of horseradish peroxidase, mucin, albumin, avidin, chloramphenicol acetyl-transferase, maltose binding protein and uracil DNA glycosylase or a combination thereof.