Designing better nano biosensors: Role of pore confinement of biomolecules

The goal of this work is to understand the role of nano confinement in designing molecular biosensors. We have been investigating micro devices incorporated with nanoporous membranes as molecular bio-sensor platforms. Ultra low detection of biomolecules is the key expectation from the new class of molecular biosensors utilizing nanomaterial. In this paper we have evaluated the role of the physical attributes of nano-porous aluminum oxide membranes in nanoconfinement and enhancing sensitivity of detection of protein biomolecules. In this biosensor configuration we have generated a sandwich assay in a high density array of nanoscale confined spaces generated by overlaying the nanoporous alumina membrane over metallic microscale sensing sites. The binding of the biomolecules results in the perturbation of the electrical double layer due to the binding of the test protein (C-reactive protein). Using electrical impedance spectroscopy (EIS), the capacitance changes in the electrical double layer associated with specific protein binding has been evaluated. The sensor performance metrics of sensitivity and dynamic range have been analyzed with changes in the pore diameter.