Exploring the Synergistic Properties of ZnGa₂O₄:Cr³⁺ and Calcium Phosphate: Longer-Lasting Persistent Luminescent Nanocomposite Using Adenosine Triphosphate As a Phosphorus Source

Abstract

Near-infrared persistent luminescence (PersL) nanoparticles are an emerging type of biomaterial that can continuously emit tissue-penetrable light. Surface functionalization techniques to improve the biological suitability of the phosphor often lead to a noticeable decrease in the luminescence capabilities of the material. In this work, Cr 3+ -doped ZnGa 2 O 4 (CZGO) nanoparticles are incorporated into an amorphous calcium phosphate (ACP) matrix to form a nanocomposite. Utilizing adenosine triphosphate (ATP) as an organic phosphorus source, the luminescence of the CZGO@ACP composite is much brighter and longer-lasting compared to bare CZGO. We found that these improved optical properties were present only when an organic phosphorus source (instead of the conventional inorganic phosphate salt, (NH 4 ) 2 HPO 4 ) was used as the ACP precursor. The chemical structure of the composite synthesized using ATP was comparatively studied with that synthesized using (NH 4 ) 2 HPO 4 . We use X-ray absorption fine structure to unravel the unique interaction between CZGO and ATP. Lastly, in vitro cytocompatibility and antibacterial tests were also performed to assess the biocompatibility of this nanocomposite.