Lanthanide-doped yttrium oxide nanoparticles can display selective upconversion properties, rendering them invaluable in the field of nanomedicine for both sensing and diagnostics. Different syntheses of Er:Y₂O₃ and Nd:Y₂O₃ nanoparticles (NPs) were studied and optimized to obtain small particles of regular shape and good crystallinity. The morphological and compositional characterizations of the nanoparticles were obtained with different techniques and showed that both Er:Y₂O₃ and Nd:Y₂O₃ NPs were well dispersed, with dimensions of the order of a few tens of nanometers. The photoluminescence and cathodoluminescence measurements showed that both Er:Y₂O₃ and Nd:Y₂O₃ NPs had good emission as well as upconversion. The nanophosphors were functionalized by a pegylation procedure to suppress unwanted reactions of the NPs with other biological components, making the NP systems biocompatible and the NPs soluble in water and well dispersed. The pegylated core/shell nanoparticles showed the same morphological and optical characteristics as the core, promoting their strategic role as photoactive material for theragnostics and biosensing.

Background: The design of multifunctional carbon based nanosystems exhibiting light-triggered hyperthermia, emission, low cytotoxicity, and drug delivery capability is of significant interest in the area of nanomaterials. In this study, we present red-emitting and photothermal carbon nanodots (Cdots-βCD/PTC) obtained by the encapsulation of hydrophobic pentacene (PTC) within Carbon nanodots (Cdots) synthesized from beta-cyclodextrin (βCD). Methods: The prepared nanostructures were investigated in terms of morphology, size, and optical properties, by absorption and emission optical spectroscopy, atomic force microscopy, dynamics light scattering, Z-potential, nuclear magnetic resonance, and infra-red spectroscopy. Molecular modelling simulation was used to investigate the geometry and the stabilization energy of the Cdots-βCD/PTC inclusion complex. Results: The as prepared Cdots-βCD/PTC demonstrated good water dispersibility, green-emission (ϕ_PL = 1.7%), and photothermal conversion (η = 17.4%) upon red-light excitation (680 nm). Furthermore, Cdots-βCD/PTC low cytotoxicity in the range 0.008 μg–0.8 μg and good interaction with albumin protein (K_SV = 2.78 ± 0.28 mL mg⁻¹) were demonstrated. Molecular simulation analysis revealed the formation of the inclusion complex with an energy of −5.32 kcal mol⁻¹, where PTC is orthogonally oriented in the βCD cavity. Conclusions: The results presented in this work highlight the potential of Cdots-βCD/PTC as a novel versatile nanosystem for biomedical applications, such as bioimaging and site-specific photothermal treatment of cancer cells.

A multi-emissive supramolecular system composed of C-nanodots, derived from β-cyclodextrin units, and Nile Red (NR) hosted in the cyclodextrin cavities (Cdots-βCD/NR) for specific and enhanced non-enzymatic phenylalanine recognition.

Emissive and electrochemically active Cu ²⁺ coordinated l -proline-derived carbon-nanodots were synthesized for specific and enhanced non-enzymatic detection of tyrosine.

A detailed review on sensing strategies for the recognition of emerging and standard biomarkers for the early diagnosis and prognosis of cardiovascular diseases, including their potential integration into point-of-care biosensor platforms.