Poly(l-lysine) Interfaces via Dual Click Reactions on Surface-Bound Custom-Designed Dithiol Adsorbates

Abstract

Surfaces modified with poly(L-lysine) can be used to immobilize selected biomolecules electrostatically. This report describes the preparation of a set of self-assembled monolayers (SAMs) from three different azide-terminated adsorbates as platforms for performing controlled surface attachments and as a means of determining the parameters that afford stable poly(L-lysine)-modified SAM surfaces having controlled packing densities. A maleimide-terminated alkyne linker was "clicked" to the azide-terminated surfaces via a copper-catalyzed cycloaddition reaction to produce the attachment sites for the polypeptides. A thiol-Michael addition was then used to immobilize cysteine-terminated poly(L-lysine) moieties on the gold surface, avoiding adsorbate self-reactions with this two-step procedure. Each step in this process was analyzed by ellipsometry, X-ray photoelectron spectroscopy, polarization modulation infrared reflection-absorption spectroscopy, and contact angle goniometry to determine which adsorbate structure most effectively produced the targeted polypeptide interface. Additionally, a series of mixed SAMs using an azidoalkanethiol in combination with a normal alkanethiol having an equivalent alkyl chain were prepared to provide data to determine how dilution of the azide reactive site on the SAM surface influences the initial click reaction. Overall, the collected data demonstrate the advantages of an appropriately designed bidentate absorbate and its potential to form effective platforms for biomolecule surface attachment via click reactions.

Adsorption of azide-functionalized thiol linkers on zinc oxide surfaces

“…Fig.3predicted favorable molecule adsorption in site-4 and site-2. The BE for unbound thiols or disuldes at slightly higher values74 seems to be hidden in the peak tail. The third peak in the S 2p spectrum centered at 168.6 eV is assigned to S-O bonding, which can be explained either with oxidation of the adsorbed thiol molecules or SAM molecules with the oxygen sublattice resulting in S-O-Zn bonding as already discussed above for the O 1s spectrum (Fig.8(b)).…”

Robust Surface Plasmon Resonance Chips for Repetitive and Accurate Analysis of Lignin–Peptide Interactions

“…46 The observed broad N 1s peak can be assigned to the carbamate group and the triazole ring. 47−49 The XPS spectrum in the C 1s region exhibits two peaks arising from C–C and C–O bonds at 284.5 and 285.8 eV, respectively, together with the O 1s and S 2p 3/2 peaks at 532.4 and 161.7 eV, respectively, which reflect the oxygen and sulfur contents of the SAM layer (Figure 2b,d,e). These results indicate formation of the triazole linkage in AA-SAM and further suggest the applicability of mixed-SAM for the covalent immobilization of lignin via click chemistry.…”

Programmable biomaterials for dynamic and responsive drug delivery

“…In the context of bacterial infections, click chemistry approaches for polymer coatings have gained headway as promising strategies for contact killing and/or fouling resistance. 96 Shakiba et al 97 have developed a dual orthogonal click reaction approach that allows for highly customizable surface modifications for subsequent small molecule and peptide immobilization. They initially designed a set of ''adsorbate'' structures that bind to gold surfaces with an azide group on the terminal end.…”