Here, we report a nanocomposite with excellent photothermal performance promising for photothermal treatment. This nanocomposite is prepared by linking Au nanorods (NRs) to NaGdF₄:18% Yb³⁺, 2%Er³⁺@NaYF₄ core–shell upconversion nanoparticles (UCNPs) with bridging of polyethylene glycol molecules. Solutions with the composite nanoparticles can be heated by the irradiation of a near-infrared 980 nm laser, and the photothermal effect in terms of temperature rise can reach 21.3 °C with excitation power density as low as 0.090 W/cm². This highly effective photothermal performance is attributed to coincidence of the emission band of the UCNPs and the absorption band of the Au NRs, which facilitates the light-to-heat conversion. The structure of the composite and the concentration of the Au NRs in the solution are also optimized through the emission intensity, green-to-red intensity ratio, and the photothermal effect in this work. Compared with previous research studies, the strength in the lower irradiation power density makes the nanocomposite promising for further photothermal treatment and temperature sensing.

中文翻译：

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金纳米棒和核壳型NaGdF _4的纳米复合材料：Yb ³⁺，Er ³⁺ @NaYF ₄上转换纳米粒子，用于温度传感

在这里，我们报道了一种具有优异光热性能的纳米复合材料，有望用于光热处理。通过将金纳米棒（NRs）与NaGdF ₄：18％Yb ³⁺，2％Er ³⁺ @NaYF ₄核-壳上转换纳米颗粒（UCNPs）与聚乙二醇分子桥联在一起，可以制备这种纳米复合材料。具有复合纳米颗粒的溶液可以通过近红外980 nm激光的照射进行加热，在温升方面的光热效应可以达到21.3°C，激发功率密度低至0.090 W / cm ²。这种高效的光热性能归因于UCNPs的发射带和Au NRs的吸收带的重合，从而促进了光热转换。在这项工作中，还通过发射强度，绿红强度比和光热效应来优化复合材料的结构和溶液中Au NRs的浓度。与以前的研究相比，较低的辐照功率密度中的强度使纳米复合材料有望用于进一步的光热处理和温度传感。