VIABILITY OF AZIDE-ALKYNE CLICK CHEMISTRY ON POLYELECTROLYTE-ANTIBODY CONJUGATION
Date
2025-12
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Publisher
University of Delaware
Abstract
Current at-home, lateral flow immunoassays rely on visual interpretation of small lines to communicate a result to users. While this method of testing is considered generally accessible due to ease of use, it significantly limits independent usage by users suffering from visual impairment, a demographic including ~10% of individuals worldwide. The necessity for help from a sighted individual or electronic interpreter compromises patient confidentiality, introduces potential to spread disease, and remains inaccessible for those facing economic disparities. While Bluetooth devices offering audio readouts have been developed, these still require access to technology and a power source. Our aim is to create a low-tech at home-testing method that can be read by touch instead of sight. Prior research in the field of tactile interfaces has shown that humans are capable of discriminating small molecular differences between surfaces through monolayer ordering and changes in mesoscale friction. Polyelectrolytes offer an interesting method of achieving surface alterations given their high degree of charge repulsion. Poly(styrene sulfonate), PSS, is a well studied polyelectrolyte known for its water solubility, stability, and negative charge repulsion. Due to these desirable properties, we are developing methods to conjugate PSS chains to a mouse IgG antibody. These attempts were approached using various bioconjugation techniques, namely click mechanisms copper-mediated azide alkyne cycloaddition (CuAAC) and strain-promoted azide alkyne cycloaddition (SPAAC). Click chemistry offers a reliable mechanism for conjugation due to its neutral charge transition state which results in quick reaction times, solvent flexibility, broad functional group tolerance, and selectivity. NuPAGE was used to assess the successful extent of conjugation. Polymers were synthesized via RAFT polymerization and functionalization was attempted through an end-chain approach. Polymerization was assessed by ¹H NMR and FTIR and results have suggested hydrolysis of the synthesized polymers results in the loss of azide functionality. Given this, current work is focused on the synthesis of an ester-free RAFT agent to ensure azide alkyne cycloaddition can occur in future conjugation attempts.