Work

Multimodal functionalization of nanodiamonds for advanced biomedical and optoelectronic applications

Year: 2025

Type: article

Abstract: Fluorescent nanodiamonds (FNDs) emit light through a specific type of photoluminescence in which light emission is very rapid and is quenched almost immediately upon removal of the light source. To enhance the fluorescent properties of FNDs, a sustainable synthesis and functionalization strategy was developed by combined physicochemical treatments. The primary nanodiamonds (NDs) were obtained using a hydrothermal method and subsequently functionalized using ascorbic acid (AA), theraphthal (TP), urea (UR), and 30 % hydrogen peroxide (H 2 O 2 ). The surface activation was enhanced by applying direct ultrasound treatment for 15 and 20 h, along with ozone (O 3 ) exposure for 0.75 and 1.5 h, followed by ultrasound for 5 h. Prior to the final functionalization step, the NDs suspensions were subjected to a cleaning process by centrifugation and filtration with 200 nm membranes. After functionalization, the samples were duly characterized by FT-IR, UV-Vis, and photoluminescence (PL) spectroscopy, ζ-potential analysis and electron microscopy, i.e., HR-TEM and SEM. From the detailed analyses, incorporation of oxidative and nitrogen-containing functional groups on the NDs was confirmed. Which was further corroborated by the appearance of a faint blue to lime-green photoluminescence (∼500–520 nm), which is attributed to nitrogen-related defects near the surface (with N–V–N as the most consistent interpretation under our conditions). It is deduced that, the combined treatment with O 3 and ultrasound effectively favored the formation of the emissive centers and significantly reduced the duration of the experimental process. FNDs developed by this method have been shown to be extremely stable and resistant to photo-bleaching, making them highly useful for long-term bioimaging applications, diagnostics and drug release systems.

Source: Nano-Structures & Nano-Objects

DOI: 10.1016/j.nanoso.2025.101576

Authors: Laura Verenis López De Arriba, Oxana V. Kharissova, Alexander L. Nikolaev, Boris I. Kharisov

Institutions: Universidad Autónoma de Nuevo León, Lomonosov Moscow State University

Language: English

Topic: Diamond and Carbon-based Materials Research

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,130

Funders: Consejo Nacional de Ciencia y Tecnología, Universidad Autónoma de Nuevo León