Femtosecond Laser-Assisted Synthesis of ZnO Nanoparticles in Solvent with Visible Emission for Temperature Sensing.

Zinc oxide (ZnO) nanoparticles (NPs) are synthesized by one-step femtosecond laser ablation of zinc powders in n-methyl pyrrolidone (NMP) at room temperature. The as-prepared ZnO NPs are fairly stable, water-soluble and have abundant surface functional groups resulting in a strong fluorescence in the visible region. By further annealing the ZnO NPs in the reacting solvent up to 120^∘C, the photoluminescence (PL) intensity of material can be significantly enhanced. Besides, the PL of ZnO NPs can change from blue to green by controlling the annealing temperature. The products exhibit excellent temperature sensing with high temperature sensitivity and a 1.3% change per ^∘C response over a linear temperature sensing range (6–84 ∘ C) in aqueous buffer, which matches well with the physiologically relevant temperatures. Hence, the ZnO nanoparticle system can serve as a promising candidate for practical fluorescent temperatures nanosensors which can be used for accurate temperature monitoring within biological systems. Water-soluble and photoluminescent ZnO NPs are synthesized by femtosecond laser ablation of zinc powders at room temperature. By further annealing, the photoluminescence intensity of the products can be significantly enhanced. The ZnO NPs exhibit excellent temperature sensing with a high sensitivity of 1.3% change per ^∘C over a linear range of 6–84^∘C in aqueous buffer, which can serve as a promising candidate for fluorescent temperature nanosensors to be used for accurate temperature monitoring within biological systems. [ABSTRACT FROM AUTHOR]