Affinity Characteristics of Histone-Derived Peptide Layer by Memory Charging Effect Using Chromatin Protein Conjugated Gold Nanoparticles

Abstract

In this study, organic-based electronic memory structure using selective recognition between histone H3 peptide and heterochromatin protein 1 (HP1) conjugated gold nanoparticles (Au NPs) as charge storage elements is demonstrated. HP1 conjugated Au NPs were formed as self-assembly monolayers (SAMs) on two different H3 peptide layers having different binding affinities to HP1. The different binding affinity was originated from methylation at 9th amino acid of lysine of the H3 peptide. Memory device was introduced in the structure of metal-pentacene-insulator-silicon (MPIS) capacitor where Au NPs SAMs were embedded between pentacene and insulator. Dielectric SiO2 layers were surface modified by 3-aminopropyl triethoxysilane (APTES) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling chemistry to immobilize two H3 peptides, methylated at lysine 9 (Met-Lys9) or unmethylated (Unmet-Lys9). The capacitance versus voltage (C-V) curves from the memory devices exhibited two distinct hysteresis of flatband voltage shifts, which demonstrated separate affinity of HP1 to H3 peptide Met-Lys9 and Unmet-Lys9, respectively.