Exploring the multifaceted potential of Ga3+ doped ZnO nanoparticles in biomedical and forensic applications

Abstract

This study presents the synthesis and multifunctional evaluation of Ga³⁺-doped Zinc oxide (ZnO) nanoparticles (NPs) using a solution combustion method with honey as a biogenic fuel. Ga³⁺ concentrations from 1 to 11 mol% were incorporated into ZnO, yielding particles with a hexagonal wurtzite structure, confirmed by X-ray diffraction (XRD), and scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) analysis verified successful Ga³⁺ integration without secondary phase formation, diffuse reflectance spectroscopy (DRS), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and photoluminescence (PL) spectroscopy. PL studies revealed a strong UV emission peak at 385 nm and broad visible emission from 420–660 nm under 248 nm excitation, highlighting their potential in anti-counterfeiting (AC) applications through UV-activated security inks and labels. For forensic applications, ZnO:1Ga³⁺ NPs demonstrated excellent visualization of latent fingerprints (LFPs), capturing detailed ridge and pore features on porous and non-porous surfaces, making them a reliable, non-destructive tool for personal identification. Biological assessments revealed notable antioxidant activity, with ZnO:1Ga³⁺ NPs effectively scavenging DPPH and H₂O₂ radicals, along with inhibiting ADP-induced platelet aggregation, suggesting therapeutic potential in mitigating oxidative stress and thrombotic conditions. Additionally, cytotoxicity tests on A549 lung cancer cells showed a dose-dependent reduction in cell viability, achieving a 68.52 % decrease at 100 μg/mL and an IC₅₀ of 164.28 μg/mL. In contrast, HEK-293 normal embryonic kidney cells retained over 90 % viability across the same concentration range, highlighting the anticancer potential of ZnO:1Ga³⁺ NPs. To evaluate the specific advantages of Ga³⁺ doping, control experiments with undoped ZnO NPs were conducted. Compared to ZnO:1Ga³⁺, the undoped ZnO showed higher cytotoxicity toward HEK-293 cells (IC₅₀ = 587.88 μg/mL), confirming the improved biocompatibility imparted by Ga³⁺. These findings establish ZnO:Ga³⁺ NPs as versatile materials suitable for AC, forensic, and biomedical applications, combining stability, biocompatibility, and targeted efficacy, making them promising candidates for advanced technological and therapeutic solutions.