Table 1: Types of covalent ligand-carrier bindings.

NameFunctional group of nanocarrierFunctional group of ligandConditions of processLiterature

Amide groupCarboxylicPrimary amineEDC, NHS, pH 7.5–8.5, 2–24 h, 4°C lub RT[98, 102108]
Thioether groupMaleimideThiolpH > 7, 4–24 h, RT[102, 111117]
Acetyl-hydrazone groupHydrazideHydroxylic24 h, 5-6°C[124]
Disulfide groupThiolThiolpH 8.0, 2–24 h, 4°C or RT[120]
Diels-AlderFuranMaleimidepH 5.5, 2–6 h, 37°C[125, 126]
“Click chemistry” (HDC)AzideAlkyneCu (I), RT, 2-3 h[131134]
StaudingerAzideTriphosphinePBS, pH 7.4, 6 h, RT[135]
Schiff’s basePrimary amineAldehydepH 9.2, RT[138]