Photogenerated lectin sensors produced by thiol-ene/yne photo-click chemistry in aqueous solution

Abstract

The photoinitiated radical reactions between thiols and alkenes/alkynes (thiol-ene and thiol-yne chemistry) have been applied to a functionalization methodology to produce carbohydrate-presenting surfaces for analyses of biomolecular interactions. Polymer-coated quartz surfaces were functionalized with alkenes or alkynes in a straightforward photochemical procedure utilizing perfluorophenylazide (PFPA) chemistry. The alkene/alkyne surfaces were subsequently allowed to react with carbohydrate thiols in water under UV-irradiation. The reaction can be carried out in a drop of water directly on the surface without photoinitiator and any disulfide side products were easily washed away after the functionalization process. The resulting carbohydrate-presenting surfaces were evaluated in real-time studies of protein-carbohydrate interactions using a quartz crystal microbalance flow-through system with recurring injections of selected lectins with intermediate regeneration steps using low pH buffer. The resulting methodology proved fast, efficient and scalable to high-throughput analysis formats, and the produced surfaces showed significant protein binding with expected selectivities of the lectins used in the study.

Synthesis of Multifunctional Cellulose Nanocrystals for Lectin Recognition and Bacterial Imaging

“…The C – CNC-Man nanocrystals were also subjected to Ricinus communis agglutinin I (RCA-120), a tetrameric lectin consisting of two As-sB-type dimers, 62,63 which specifically recognize galactosyl residues ( K a for galactose is 2.2 × 10 3 M −1 ), 64 whereas mannosyl groups show no affnity. 65 As shown in Figure 4AIII, no dramatic precipitation was observed within 30 min incubation with this lectin. The emission spectra of C – CNC-Man suspensions in the absence of lectin or after interaction with lectin were recorded (Figure 4C).…”

A Comparative Study of Thiol‐Terminated Surface Modification by Click Reactions: Thiol‐yne Coupling versus Thiol‐ene Michael Addition

“…In 2012, Wu et al created UV lithography based patterning of alkene and alkyne‐functionalized polymers on various substrates via TEC and TYC reactions . In another study of modification of polymer surfaces published in 2012, Norberg et al produced lectin sensors by utilizing TEC and TYC reactions of thiolated carbohydrates on alkene and alkyne‐functionalized polystyrene . In a valuable effort published in 2013, Bhairamadgi et al did a study comparing TEC and TYC on oxide‐free Si(111) surfaces.…”

Metal‐Free Click Chemistry Reactions on Surfaces

“…TEC has also been used to modify other polymer surfaces such as polystyrene. For example, Norberg et al described the modification of alkene or alkyne‐functionalized polystyrene coated onto gold surfaces that were used in the immobilization of glycoconjugates via TEC and TYC chemistries . Initial surface functionalization of commercially avaliable polystyrene‐coated quartz crystal microbalance (QCM) crystals involved treatment of the polymeric coating with a NHS‐activated fluorophenylazide derivative, followed by nucleophilic acyl substitution reactions to introduce the ene and yne functionality ( Figure ).…”