Small：尺寸可调COFs纳米粒子--具有视觉传感的一维光子晶体

本文要点：

1. 一维光子晶体(1D光子晶体)因其对环境变化的高度敏感性而成为优秀的传感平台。然而，通过1D光子晶体有效地将共价有机框架(COFs)和分析物之间的微观相互作用转化为宏观光学响应以进行直观检测是一个巨大的挑战。

2. 在这里，作者提出了一种分步诱导合成策略，首次实现了均匀纳米级COFs(60–80nm)的尺寸可控合成，从而产生了高质量的COF层。这一进步使COF的1D PCs能够展现多样的色彩变化和可控的饱和度。

3. 值得注意的是，COF层与无机氧化物、有机聚合物和金属有机框架(MOFs)的优异相容性导致这些1D PCs呈现明亮的颜色。

4. 至关重要的是，介孔材料的引入使1D PCs实现了对挥发性有机化合物(VOCs)吸附和识别功能的深度整合。制造的COF/MOF 1D PC可以区分12种挥发性有机化合物，并通过颜色变化直观地检测不同浓度(0-80 g m-3)的挥发性有机化合物，响应时间不到1秒。

5. 特别是，COF的1D PC可以转移到柔性基板上，同时保留挥发性有机化合物视觉传感。这些特性凸显了COF 1D PCs在工业环境中进行实时VOC监控的潜力。

Figure 1. Schematic diagram of 1D PCs constructed by COF and different materials for VOC visual sensing.

Figure 2. a) Schematic diagram of the preparation of TAPB-BTCA-COF. b) SEM images and c) corresponding size distribution of TAPB-BTCA-COF nanoparticles with different sizes. d) FT-IR spectra, e) XRD patterns, f) N2 adsorption-desorption isotherms and g) TGA thermograms of TAPB-BTCACOF nanoparticles with different sizes. h) Digital photo of large-scale synthesized TAPB-BTCA-COF nanoparticles. i) Digital photo and j) SEM image of large-scale preparation of TAPB-BTCA-COF nanoparticles with corresponding particle size distribution statistic.

Figure 3. a) SEM images of TAPB-BTCA-COF particles prepared with different amounts of CH3COOH and b) the corresponding size distribution.

Figure 4. a) SEM images of TAPB-BTCA-COF and TiO2@PDA layers and the corresponding RI. b) Schematic diagram of the preparation process of COF-based 1D PC. c) Digital photos of COF-based 1D PCs with TAPB-BTCA-COF concentrations of 2.3–3.7 wt.% and the corresponding cross-sectional SEM images. d) Reflection spectra of COF-based 1D PCs with TAPB-BTCA-COF concentrations of 2.3–3.7 wt.%. e) Digital photos of COF-based 1D PCs with 1–6 stacks and the corresponding cross-sectional SEM images. f) Reflection spectra of COF-based 1D PCs with 1–6 stacks.

Figure 5. a) Schematic diagram of different assembly materials used for constructing COF-based 1D PCs. b) Digital photos of COF-based 1D PCs, constructed with the following materials in combination with TAPB-BTCA-COF: SiO2 (PC 1), ZrO2 (PC 2), ZnO (PC 3), PMMA (PC 4), PS (PC 5), MIL101(Cr) (PC 6), ZIF-8 (PC 7), UIO-66 (PC 8), NH2-MIL-53(Al) (PC 9) and NH2-MIL-88B (PC 10). c) Wavelength shifts of PC 6 when exposed to 12 kinds of saturated VOC vapors. d) Refractive indexes of 12 kinds of VOCs. e) Flatten waterfall plot of reflection spectra of PC 6 when exposed to different concentrations of toluene vapor. f) Frequency variations of TAPB-BTCA-COF and MIL-101(Cr) layers when alternating exposure to toluene vapor and air measured with QCM-D. g) Frequency variations of TAPB-BTCA-COF layer when exposed to different concentrations of toluene vapor measured with QCM-D.

Figure 6. a) Schematic diagram of COF-based 1D PC transferred from the tape. b) Digital photos of COF-based 1D PCs with different structural colors on tape. c) Reflection spectra of COF-based 1D PCs on tape. d) Digital photos of COF-based 1D PC with bendability, water flushing, and resistance to finger rubbing. e) Digital photos of COF-based 1D PC transferred to different objects. f) Digital photos of color change in transferred COF-based 1D PC before and after exposure to toluene vapor. 

https://doi.org/10.1002/smll.202408201