Resorc[4]arene-functionalized MWCNTS for the development of new highly sensitive immunosensors

One of the main problems in the development of immunosensors is to overcome the complexity of binding antibodies onto the sensor surface, thus leading to a loss of sensitivity.[1] For this reason, in the last twenty years, macrocyclic species such as calix[4]arene has been used for the site-directed immobilization of antibodies in the correct end-on orientation.[2] In the last years, due to their configuration and unique molecular recognition properties, resorcinol-based cyclooligomes, namely resorc[4]arenes,[3] have been used for the development of highly sensitive immunosensors.[4] In this project, new resorc[4]arene-based derivatives have been designed and synthesized for covalent grafting by nucleophilic substitution or cycloaddition of multi-walled carbon nanotubes, a versatile material endowed with great electric properties, high electroactive surface area and biocompatibility.[5] The prepared materials have been fully characterized by both morphological (FE-SEM and AFM) and spectroscopical (XPS) techniques before the construction of the immunosensors. Finally, the modified electrodes have been characterized by DPV and CV and IgG antibodies for the SARS-CoV-2 spike protein S1 (SPS1) were immobilized on their surface. The developed immunodevice was then employed in the analysis of SPS1 standard solutions as a proof of concept for COVID-19 immunosensor.