Cross-reactivities in conjugation reactions involving iron oxide nanoparticles

• Shoronia N. Cross,
• Katalin V. Korpany,
• Hanine Zakaria and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2025, 16, 1504–1521, doi:10.3762/bjnano.16.106

• IONPs (IONP-3,4-DHBA) as a platform upon which carbodiimide coupling can be used to conjugate clickable small molecules for further functionalization using two common click reactions, namely, the copper-catalyzed azide–alkyne cycloaddition (CuAAC), and the thiol–maleimide Michael addition reactions

• for the preparation of functional IONPs capped with either alkynes or azides [8][13][17][18][19][20][21][22][23][24][25][26][27]. The thiol–maleimide Michael addition reaction is another commonly employed click reaction [28][29][30][31], which can be performed at room temperature by simply mixing

• )phosphine (THPP, Figure 1h). We probe cross-reactivities in the CuAAC and thiol–maleimide Michael addition reactions using two dyes, Cy5-azide (Figure 1i) and Cy3-maleimide (Figure 1j), respectively. Oxidation of 3,4-DHBA forms an o-quinone (Figure 1a), which has a greatly diminished affinity for the IONP