# Synthesis and Characterization of Luminescent and Antibacterial Europium-Titanate nanotubes

## TL;DR

Researchers developed luminescent and antibacterial nanotubes by adding europium ions, which could be useful in biomedical applications.

## Contribution

The study introduces a novel method to functionalize titanate nanotubes with europium ions to enhance both luminescence and antibacterial properties.

## Key findings

- Eu3+ functionalized TiNts showed red emission from Eu3+ transitions and improved visible light absorption.
- TiNts/Eu exhibited inhibition zones of 5 mm against Staphylococcus aureus and 11 mm against Escherichia coli.
- The fully coordinated hybrid TiNts[Eu(tta)3phen] showed enhanced antibacterial activity with 14 mm inhibition zones.

## Abstract

Antibacterial resistance poses a growing threat to public
health
by reducing the effectiveness of conventional antibiotics. Nanohybrid
materials, such as titanate nanotubes (TiNts), represent a promising
alternative owing to their low cost, chemical stability, and biocompatibility.
In this study, we functionalized TiNts with europium ions (Eu3+) to enhance both optical properties and antibacterial activity.
The incorporation of Eu3+ extended the material’s
absorption from the ultraviolet into the visible region. Two luminescent
hybrids were obtained: (i) TiNts/Eu, prepared by Eu3+ adsorption
onto nanotubes, synthesized via an alkaline hydrothermal treatment,
and (ii) TiNts­[Eu­(tta)3phen], produced through coordination
of Eu3+ ions with the TiNts and the organic ligands thenoyltrifluoroacetone
(tta) and 1,10-phenanthroline (phen). TiNts/Eu displayed the characteristic
red emission of Eu3+, arising from the 5D0 → 7F
J
(J = 0–4) transitions, confirming efficient energy
transfer from both the inorganic host and organic ligands. The introduction
of tta and phen further improved the material’s light absorption
in the UV region (200–400 nm). Antibacterial assays revealed
inhibition zones of 5 and 11 mm against Staphylococcus aureus and Escherichia coli, respectively, for TiNts/Eu.
In contrast, the fully coordinated hybrid TiNts­[Eu­(tta)3phen] exhibited enhanced antibacterial activity, with inhibition
zones of 14 mm. These findings highlight Eu3+ functionalized
titanate nanohybrids as highly potent antimicrobial agents and versatile
luminescent materials for biomedical applications.