Noninvasive and sensitive thermometry of a single living cell is crucial to the analysis of fundamental cellular processes and applications to cancer diagnosis. Optical fibers decorated with temperature-sensitive nanomaterials have become widely used instruments for biosensing temperature. However, current silica fibers exhibit low compatibility and degradability in biosystems. In this work, we employ spider silks as natural optical fibers to construct biocompatible thermometers. The spider silks were drawn directly from Araneus ventricosus and were decorated with core–shell upconversion nanoparticles (UCNPs) via a photophoretic effect. By measuring the fluorescence spectra of the UCNPs on the spider silks, the membrane temperature of a single breast cancer cell was obtained with absolute and relative sensitivities ranging from 3.3 to 4.5 × 10^–3 K^–1 and 0.2 to 0.8% K^–1, respectively. Additionally, the temperature variation during apoptosis was monitored by the thermometer in real time. This work provides a biocompatible tool for precise biosensing and single-cell analysis.

中文翻译：

---

上转换纳米粒子装饰的蜘蛛丝作为单电池温度计

单个活细胞的非侵入性和灵敏测温对于分析基本细胞过程及其在癌症诊断中的应用至关重要。用对温度敏感的纳米材料装饰的光纤已成为广泛用于生物传感温度的仪器。但是，目前的二氧化硅纤维在生物系统中显示出低的相容性和降解性。在这项工作中，我们采用蜘蛛丝作为天然光纤来构建生物相容性温度计。蜘蛛丝直接取自Araneus ventricosus并通过光致效应用核-壳上转换纳米颗粒（UCNP）装饰。通过测量蜘蛛丝上的UCNPs的荧光光谱，可以获得单个乳腺癌细胞的膜温度，其绝对和相对灵敏度分别为3.3至4.5×10 ^–3 K ^–1和0.2至0.8％K ^–1，分别。另外，通过温度计实时监测细胞凋亡期间的温度变化。这项工作为精确的生物传感和单细胞分析提供了生物相容性工具。