Novel attachment method provides boost to biosensor development

A versatile method for attaching precise amounts of biomolecules and even cells to electrically conductive surfaces could lead to a new generation of nanoscale biosensors with broad applicability in cancer diagnostics and basic research.

This research, led by Muhammad Yousaf, Ph.D., a member of the Carolina Center of Cancer Nanotechnology Excellence (CCNE), appears in the Journal of the American Chemical Society.

To create their new attachment method, the investigators took advantage of the unique chemical properties of the molecule p-benzoquinone. This molecule will not only react with a variety of chemical groups found on biomolecules and cell surfaces, but it will produce a measurable electrochemical signal when layered on an electrically active surface, which indicates the progress of any chemical reactions. Being able to track the progress of any attachment reaction gives investigators important details on the final density of any biomolecules used to coat a potential biosensor.

To demonstrate the utility of their method, the Carolina CCNE team created a monolayer of p-benzoquinone on a gold surface and then used a microarray printer to place spots of biomolecule on the monolayer. The researchers then used a technique known as cyclic voltammetry to measure the resulting density of biomolecule attached to the surface.

In a subsequent demonstration, the researchers used the same approach to attach a cell-surface binding peptide, known as RGD, to the monolayer. They then added cultured cells to this modified monolayer and found that the cells attached themselves to the binding molecule but not to anywhere else on the gold surface.

This work is detailed in a paper titled, “Immobilization of ligands with precise control of density to electroactive surfaces.” This paper was published online in advance of print publication. An abstract for this paper is not yet available.