Detection of non-conductive nanoparticles by Nanoparticales Imprinted Matrices (NAIMs)

The selective recognition of nanoparticles (NPs) can be achieved by nanoparticles imprinted matrices (NAIMs) by which NPs are imprinted in a matrix followed by their removal to form voids that can reuptake the original NPs. The recognition depends on supramolecular interactions between the matrix and the shell of the NPs, as well as on the geometrical suitability of the NPs to fit into the imprinted voids. Thus far the NAIMs approach was limited to conducting NPs specifically to metallic NPs. Herein, the NAIMs approach was expanded to enable the detection of non-conductive NPs. Silica nanoparticles (SiO₂-NPs) were preadsorbed onto a conductive surface followed by electrografting of p-aryldiazonium salts (ADS). The thickness of the matrix was carefully controlled by the applied potential. The SiO₂-NPs were removed by dissolution with diluted HF solution. The recognition of the NAIMs was determined by reuptaking the original SiO₂-NPs by the imprinted voids.