Enhancement of electronic effects at a biomolecule-inorganic interface by multivalent interactions

The binding of peptides and proteins through multiple weak interactions is ubiquitous in nature. Biopanning has been used to hijack this multivalent binding for the functionalization of surfaces. For practical applications it is important to understand how multivalency influences the binding interactions and the resulting behaviour of the surface. Considering the importance of optimization of the electronic properties of surfaces in diverse electronic and optoelectronic applications, we study here the relation between the multivalency effect and the resulting modulation of the surface work function. We use 12-mer peptides, which were found to strongly bind to oxide surfaces, to functionalize indium tin oxide (ITO) surfaces. We show that the affinity of the peptides for the ITO surface, and concurrently the effect on the ITO work function, are linearly affected by the number of basic residues in the sequence. The multivalent binding interactions lead to a peptide crowding effect, and a stronger modulation of the work function for adodecapeptide than for a single basic amino acid functionalization. The bioderived molecular platform presented herein can pave the way to a novel approach to improve the performance of optoelectronic devices in an eco-friendly manner.

Automated summary

The binding of peptides and proteins through multiple weak interactions is widely observed. Biopanning has been used to exploit this multivalent binding for surface functionalization. Understanding the influence of multivalency on binding interactions and surface behavior is crucial for practical applications. In this study, we investigate the relationship between multivalency and the modulation of the surface work function using 12-mer peptides to functionalize indium tin oxide (ITO) surfaces. We demonstrate that the affinity and modulation of the ITO work function by the peptides are linearly dependent on the number of basic residues in the sequence. The multivalent binding interactions result in a peptide crowding effect, leading to a stronger modulation of the work function compared to single amino acid functionalization. This bioderived molecular platform has the potential to eco-friendly enhance optoelectronic device performance.