Multivalent interactions play show enhanced strength and better selectivity compared to monovalent interactions, but they are much less understood due to their complexity.

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Using AFM-based single molecule force spectroscopy. we detect molecular interactions in the range of a few piconewtons to several nanonewtons and correlate them with the formation and subsequent breaking of one or several bonds and assign these bonds. We use a multifunctional polymer that is covalently attached to an AFM cantilever tip to contact a polymer layer of the multifunctional polymer bound to a solid substrate. Varying the crosslinking state of the polymer layer, we find that bonds of intermediate strength (non-covalent), like coordination bonds, give the highest multivalent bond strength, even outperforming strong (covalent) bonds.

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Multivalent interactions can be used to design stable and durable polymer coatings, in particular keeping the number of non-covalent interactions at a high level.

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Literature: 

N. Schwierz, D. Horinek, S. Liese, T. Pirzer, B. N. Balzer, T. Hugel & R. R. Netz
On the relationship between peptide adsorption resistance and surface contact angle: A combined experimental and simulation single-molecule study
J. Am. Chem. Soc., 134 (48), 19628 (2012). https://doi.org/10.1021/ja304462u

 

B. N. Balzer, M. Gallei, K. Sondergeld, M. Schindler, P. Müller-Buschbaum, M. Rehahn & T. Hugel
Cohesion mechanisms of polystyrene-based thin polymer films
Macromolecules, 46 (18), 7406 (2013). https://doi.org/10.1021/ma401173y
 
B. N. Balzer, S. Micciulla, S. Dodoo, M. Zerball, M. Gallei, M Rehahn, R. v. Klitzing & T. Hugel
Adhesion property profiles of supported thin polymer films
ACS Applied Materials & Interfaces, 5 (13), 6300 (2013). https://doi.org/10.1021/am4013424

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M. Lallemang, L. Yu, W. Cai, K. Rischka, A. Hartwig, R. Haag, T. Hugel & B. N. Balzer

Multivalent non-covalent interactions lead to strongest polymer adhesion

Nanoscale, 14, 3768 (2022). http://dx.doi.org/10.1039/D1NR08338D​

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M. Ibrahim, C. Wenzel, M. Lallemang, B. N. Balzer & N. Schwierz

Adsorbing DNA to mica by cations: influence of valency and ion type

Langmuir,  39 (44), 15553 (2023). https://doi.org/10.1021/acs.langmuir.3c01835

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