Integrated analytical platforms for the comprehensive characterization of bioconjugated inorganic nanomaterials aiming at biological applications

Abstract

Nowadays, the synthesis of new multifunctional engineered nanoparticles (ENPs) constitutes a research topic of increasing importance in nano(bio)technology. Such ENPs can be synthesized from a large variety of materials, and are inorganic nanoparticles that are highly competitive in biomedical applications due to their unique optoelectronic properties. Most bioapplications require proper and controlled surface functionalization, which not only defines their interactions with the environment ultimately affecting their colloidal stability and biocompatibility, but also allows the assembly of functional biomolecules to be capable of providing a controlled targeting and delivery of nanoparticles (mandatory for chemical sensing or bioimaging purposes). In this context, the precise control of the composition and chemical quality of the starting nanomaterial is required to ensure their subsequent functionalization. Currently, there is no definitive methodology to provide such a complete characterization, and therefore, an integration of different analytical approaches is required, such as the on-line coupling of size-based separation techniques (AF4) to molecular (UV-vis) and elemental detectors (ICP-MS). This tutorial review is intended to provide a perspective on different techniques that can be integrated into multidisciplinary analytical platforms for sizing as well as the optical and elemental characterization of engineered structured inorganic nanomaterials before and after their bioconjugation to biomolecules.