Odd-Even Effect in Peptide SAMs-Competition of Secondary Structure and Molecule-Substrate Interaction

Advances in single-molecule electrical transport studies of peptides

The charge transport between peptide molecules is one of the crucial factors in sustaining various biochemical processes within biological organisms. Understanding the charge transport processes between peptide molecules is of great significance for further investigating life reaction processes. Through single-molecule electronic characterization techniques, we have reviewed the effects of peptide molecular stuctures and external experimental factors on charge transport. Additionally, we have summarized the latest research on supramolecular interactions between peptide chains, particularly focusing on the even-odd effect. This not only enhances our understanding of the charge transport mechanisms between peptide molecules but also lays a solid theoretical foundation for the widespread application of peptide molecules in fields such as biological devices.

Odd-Even Effects in the Structure and Thermal Stability of Carboxylic Acid Anchored Monolayers on Naturally Oxidized Aluminum Surface

Self-assembled monolayers (SAMs) are broadly used for molecular engineering of surfaces and interfaces, which demands control over their structure and properties. An important tool in this context is the so-called odd-even effects exploiting the dependence of the SAM structure on the parity of the number of building blocks forming the backbone of SAM-building molecules. Even though these effects influence parameters crucial for SAM applications, they have been mainly studied on coinage metals (Au and Ag) until now. Here, using the series of biphenyl-substituted carboxylic acids (BPnCOO, n = 0-4), we show that structural odd-even behavior occurs as well on technologically relevant surface of naturally oxidized aluminum (representative of other oxide surfaces), with the even-numbered monolayers exhibiting higher packing density and lower molecular inclination than the odd-numbered analogs. Despite these structural changes, the SAM desorption energy remains nearly constant at a high value (∼1.5 eV) making BPnCOO/AlOx a promising system for organic electronics applications.

Peptide-based self-assembled monolayers (SAMs): what peptides can do for SAMs and vice versa

Self-assembled monolayers (SAMs) represent highly ordered molecular materials with versatile biochemical features and multidisciplinary applications. Research on SAMs has made much progress since the early begginings of Au substrates and alkanethiols, and numerous examples of peptide-displaying SAMs can be found in the literature. Peptides, presenting increasing structural complexity, stimuli-responsiveness, and biological relevance, represent versatile functional components in SAMs-based platforms. This review examines the major findings and progress made on the use of peptide building blocks displayed as part of SAMs with specific functions, such as selective cell adhesion, migration and differentiation, biomolecular binding, advanced biosensing, molecular electronics, antimicrobial, osteointegrative and antifouling surfaces, among others. Peptide selection and design, functionalisation strategies, as well as structural and functional characteristics from selected examples are discussed. Additionally, advanced fabrication methods for dynamic peptide spatiotemporal presentation are presented, as well as a number of characterisation techniques. All together, these features and approaches enable the preparation and use of increasingly complex peptide-based SAMs to mimic and study biological processes, and provide convergent platforms for high throughput screening discovery and validation of promising therapeutics and technologies.