Nanomaterials

Breast cancer is the most common cancer in women worldwide, with a high mortality rate. Moreover, the treatments currently used to address this disease are sometimes ineffective and cause numerous side effects. For this reason, the search for new treatments that can overcome these challenges is a growing field of research. One potential solution under investigation is the use of mesoporous silica nanoparticles (MSNs). These materials possess excellent properties, making them attractive as starting platforms for various compounds. In this study, different compounds with distinct properties were anchored onto these nanoplatforms. The first is polyethyleneimine (PEI), which, when formulated within the nanoparticle, increases its bioavailability. The second is folic acid (FA), a molecule that enables active targeting of tumor cells. Finally, an organotin(IV) complex was incorporated via two different anchoring strategies to provide therapeutic action. This multifunctional platform thus combines three activities simultaneously. MTT assay studies revealed that the final material, MSN-TEDTH-PEI-FA-TR-Sn, demonstrates potential against the MCF-7 tumor cell line while showing no toxicity to the healthy Hek 293T cell line. These findings make it an interesting candidate for future in vivo trials.

Zero-dimensional (0D) rare-earth-based metal halides show great potential in photonic and optoelectronic applications owing to their high stability, strong exciton confinement, and tunable energy levels. However, the weak absorption and narrow 4f-4f transitions of rare-earth ions limit their performance. To address this, a series of Sb³⁺-doped Cs₃LnCl₆ (Ln: Yb, La, Eu, Ho, Ce, Er, Tb, Sm, Y) nanocrystals were synthesized via a hot-injection method to study the role of Sb³⁺ doping. Sb³⁺ incorporation induces strong broadband self-trapped exciton (STE) emission from Jahn–Teller-distorted [SbCl₆]³⁻ units and enables efficient energy transfer from STEs to rare-earth ions. As a result, the photoluminescence intensity and spectral tunability are improved, accompanied by bandgap narrowing and enhanced light absorption. Different lanthanide hosts exhibit distinct luminescence behaviors: La-based materials show dominant STE emission, while Tb-, Er-, Yb-, Ho-, and Sm-based systems display STE-mediated energy transfer and enhanced f-f emission. In Eu- and Ce-based hosts, unique mechanisms involving Eu²⁺/Eu³⁺ conversion and Ce³⁺ → STE energy transfer are observed. Moreover, composition-dependent emissions in Sb³⁺-doped Cs₃Tb/EuCl₆ enable a dual-mode color and spectral encoding strategy for optical anti-counterfeiting. This study highlights the versatile role of Sb³⁺ in tuning electronic structures and energy transfer, offering new insights for designing high-performance rare-earth halide materials for advanced optoelectronic applications.

The agrifood sector produces considerable waste, offering opportunities for sustainable innovation. In the coffee industry, spent coffee grounds (SCG) can be valorized to generate eco-friendly nanomaterials such as nano zerovalent iron (nZVI), widely applied in soil and water remediation. In this study, green nZVIs were synthesized using SCG hydromethanolic extracts and FeCl₃, subsequently characterized, and assessed for cytotoxicity. High-performance liquid chromatography with diode-array detection (HPLC-DAD) was employed to identify hydroxycinnamic acids, caffeine, and trigonelline in the SCG extracts. Preliminary remediation assays were conducted with seven contaminants, with venlafaxine selected for detailed pH and kinetic studies. Characterization of nZVIs included SEM and EDS analyses, which revealed spherical nZVI particles (72–83 nm) composed of carbon (47%), oxygen (34%), and iron (16%). Dynamic light scattering (DLS) measurements indicated the presence of smaller particles (15–23 nm). Thermogravimetric analysis (TG) confirmed a residual mass of about 20% at 1400 °C. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed phenolic compound incorporation, while X-ray diffraction (XRD) revealed an amorphous structure. The particles exhibited magnetic behavior and showed no cytotoxicity toward MRC-5 and U87 cell lines. Among the tested contaminants, venlafaxine displayed the highest removal efficiency in remediation tests. Compared with chemically synthesized nZVI, the green version exhibited enhanced stability, attributed to the presence of surface-bounded organic matter. Overall, this sustainable and cost-effective approach to produce nZVI from SCG provides an innovative method for waste valorization and environmental remediation.