Abstract

Hierarchically Organized Block Copolymer-Nanopore Electrode Arrays for Electrochemical Biosensing of Disease Biomarkers

Paul Bohn, Arthur J. Schmitt Professor of Chemical and Biomolecular Engineering and Professor of Chemistry and Biochemistry, University of Notre Dame

Hydrophobic gating in biological transport proteins is regulated by stimulus-specific switching between filled and empty nanocavities, endowing them with selective mass transport capabilities. Inspired by these, solid-state nanochannels have been integrated into functional materials to realize electrochemical biosensors with integral mass transport control. Hierarchically organized structures are composed of polystyrene-b-poly(4-vinyl)pyridine (PS-b-P4VP) block copolymer on two-electrode nanopore electrode arrays (BCP@NEAs) housing target-specific enzymes. The BCP enables potential-responsive gating, making it possible to capture and confine analyte species in the attoliter-level NEA volume, enabling redox cycling and current amplification factors >100X. The enzyme-coupled sensing capabilities have been demonstrated with a variety of substrates, including cytokines (IL-6, TNF-alpha), metabolites from lipid nanoparticle degradation, and environmentally-relevant markers. Limits-of-detection <70 fM are obtained in favorable cases. The mass transport-controlled sensing platform described is relevant to next-generation point-of-care devices.