Ultrastable PEGylated Calixarene-Coated Gold Nanoparticles with a Tunable Bioconjugation Density for Biosensing Applications

Many in vivo and vitro applications using gold nanoparticles (AuNPs) require (i) their PEGylation, as it increases stability prevents nonspecific protein adsorption, (ii) conjugation to biomolecules, that provides them with specific recognition properties. Currently, the functionalization of AuNPs is based on thiol chemistry suffers from two major drawbacks: Au–S bond labile confers limited chemical robustness organic layer, control over bioconjugation density highly challenging. We report here a novel strategy calix[4]arene-tetradiazonium platforms for coating robust PEG layer controlled bioconjugation. were first modified functional calix[4]arene-diazonium salt bearing three chains ended by methoxy group one carboxyl group. The resulting particles showed excellent colloidal stabilities, compared similar systems obtained via classical chemistry, could even be dispersed human serum without degrading or aggregating. In addition that, groups protruding allowed amide formation amine-containing biomolecules such peptides. was grafting mixed layers nonfunctional PEGylated calix[4]arenes, varying number carried subsequently capacity while preserving dense protective shell. Finally, we used these nanomaterials, peptide aptamers, biosensing cancer biomarker, Mdm2.