Probing into Bifunctional Luminomagnetic Upconverting Nanorods for External Magnetic Tracking Applications

A strategy to synthesize a bi‐functional luminomagnetic Er3+/Yb3+‐doped NaGdF4 nanorods, using a facile base‐catalyzed hydrothermal method, is demonstrated. This luminomagnetic nanorods material is investigated for its structural/microstructural, optical, and magnetic properties to validate applications in the bio‐medical field. The as‐synthesized nanorods exhibit highly intense green emission peaking at 539 nm upon excitation with 980 nm wavelength using a diode laser. Further, the effect of 980 nm laser power on the emission spectrum of these Er3+/Yb3+‐doped NaGdF4 nanorods is investigated and a mechanism for the upconversion process is proposed. The CIE (French: International Commission on Illumination) coordinates at all the input laser powers lie in the close vicinity of x=0.28 and y=0.68 and thus suggest the color purity of the Er3+/Yb3+‐doped NaGdF4 nanorods. Moreover, these nanorods also exhibit strong paramagnetic behavior as confirmed by M−H and M−T measurements. We have also demonstrated the application of these nanorods for external magnetic field tracking applications. The cellular cytotoxicity analysis of the nanorods against the MDA‐MB‐231 and MCF‐10 A cell lines suggests their applicability in biomedical applications. Thus, the co‐existence of luminescence and magnetism in a single entity suggests its suitability as a bi‐functional nanoprobe in biological applications. A strategy to design a bi‐functional luminomagnetic Er3+/Yb3+ ‐doped NaGdF4 nanorods using a facile base‐catalyzed hydrothermal method. The as‐synthesized nanorods exhibits highly intense green emission at 539 nm upon 980 nm excitation wavelength. Moreover, this nanorods also exhibits strong paramagnetic behavior as confirmed by M−H measurements. Thus, the co‐existence of luminescence and paramagnetism in a single entity suggests its potential applications as a bimodal nanoprobe in biomedical applications.