Single‐Molecule Force Spectroscopy Reveals Multiple Binding Modes between DOPA and Different Rutile Surfaces

Abstract

Inspired by marine mussela dhesive systems, numerous3 ,4-dihydroxyphenylalanine(DOPA)-containing surface coating materials have been recently designed. It is well known that DOPA has as tronga dhesion ability to different kinds of wet surfaces. However,t he molecular mechanism of DOPAa dhesionr emains elusive. Recent biophysical studies of DOPAa dhesion by both surfacef orce apparatus (SFA) and atomic force microscopy (AFM) suggest that DOPAc an bind to aw ide range of surfaces exhibitingd iverse chemical properties through differentb inding mechanisms. Here, using AFM-based single-molecule force spectroscopy,w es how that even for chemically well-defined crystal surfaces, DOPAc an bind to them by multiple binding modes. The binding forces between DOPAa nd differentr utile TiO 2 surfacesc an vary within ab road range from 40-800 pN at ap ulling speed of 1000nms À1 and are largely dependent on the surface properties. Our findings indicatet hat the local chemicale nvironment can greatly affect DOPAa dhesion, and that single-molecule force spectroscopy is au nique tool to reveal the heterogeneity of DOPAa dhesiont ot he same surface.

Molecular design principles of Lysine-DOPA wet adhesion

“…3a ). The dominant peak located at lower force matches previously reported values and could mainly result from the rupture of individual DOPA–surface interactions 9 , 36 , 37 . The second broad peak may be attributed to the synergistic binding of (K Y ) to the TiO 2 .…”

“…As a consequence, an observable detaching force was measured for the interaction with PS. However, unlike DOPA that uses its catechol to form bidentate coordination bonds with TiO 2 surface, Phe cannot form such stable interactions with TiO 2 , and the charge interaction between Lys and TiO 2 surface is not strong enough to be detected by this technique 9,10,36 . Consequently, we failed to observe detectable rupture events for the interaction of (KF) and TiO 2 surface.…”

Blue light-induced low mechanical stability of ruthenium-based coordination bonds: an AFM-based single-molecule force spectroscopy study

“…Atomic force microscopy (AFM)-based SMFS (AFM-SMFS) has become a powerful tool for detecting protein folding, metal-ligand bond strength, surface adhesion, and many other biomechanical interactions, [33][34][35][36][37][38] which cannot be uncovered by other traditional thermodynamics methods. Here, we exploit AFM-SMFS to study the mechanical strength of a Ru-pyridine complex, using synthesized single-chain polymeric nanoparticles as pyridine cores, which are ubiquitous in natural products and widely used for the construction of supramolecular compounds.…”

Direct Observation of the Interplay of Catechol Binding and Polymer Hydrophobicity in a Mussel-Inspired Elastomeric Adhesive

“… 23 When the surfaces of main group metal oxides such as SiO 2 and Al 2 O 3 were studied, lower adhesion strengths were found, and it has been suggested that they interact exclusively through hydrogen bonding in ambient conditions. 30 Although AFM studies provide detailed information on binding energies, there are unresolved inconsistencies in the values of DOPA-TiO 2 pull-off forces in the literature. 23 , 29 , 32 …”