Meng Xiangyu, Wang Yuening, Song Xiaoyu, Zhang Mingjian, Yu Jian, Qiu Lin, Lin Jie, Wang Xiaotian
School of Chemistry, Beihang University, Beijing 100191, China.
Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, P. R. China.
ACS Appl Mater Interfaces. 2023 Oct 18;15(41):48818-48825. doi: 10.1021/acsami.3c10565. Epub 2023 Oct 5.
Volatile organic compounds (VOCs) are common environmental pollutants and important biomarkers for early diagnosis of lung cancer. However, aldehydes are difficult to detect directly due to their small Raman scattering cross-section and gaseous phase. Here, a Ag-coated ternary layered double hydroxide (LDH) was designed for the detection and identification of various aldehydes. The specific surface area of CoNi-LDH was increased by doping Fe, which provides abundant active sites to capture gas molecules. Furthermore, the energy band gap () was decreased due to the local amorphous FeCoNi-LDH with an extended band tail, promoting the excitonic transition of Fe(CoNi)-LDH. In addition, the Fermi level of Ag prevented the recombination of electron-hole pairs of Fe(CoNi)-LDH, providing a new bridge for charge transfer between the substrate and the molecule. Ag/Fe(CoNi)-LDH presented excellent surface-enhanced Raman scattering (SERS) performance for aldehyde VOCs by modification with 4-aminothiophenol (4-ATP) to capture aldehydes and realized the detection of benzaldehyde (BZA) at 10 ppb. The enhancement and Raman shift of the b mode indicated the contribution of chemical enhancement to the SERS system, so the substrate presented good uniformity. The recycling of the SERS substrate is realized based on the reversibility of the Schiff base reaction. These results manifested that Ag/FeCoNi-LDH has a wide prospect in the application in the trace detection of aldehydes.
挥发性有机化合物（VOCs）是常见的环境污染物，也是肺癌早期诊断的重要生物标志物。然而，由于醛类的拉曼散射截面小且处于气相，难以直接检测。在此，设计了一种银包覆的三元层状双氢氧化物（LDH）用于检测和识别各种醛类。通过掺杂铁提高了CoNi-LDH的比表面积，为捕获气体分子提供了丰富的活性位点。此外，由于具有扩展能带尾的局部非晶态FeCoNi-LDH，其能带隙（）减小，促进了Fe(CoNi)-LDH的激子跃迁。此外，银的费米能级阻止了Fe(CoNi)-LDH的电子-空穴对复合，为底物与分子之间的电荷转移提供了新的桥梁。通过用4-氨基硫酚（4-ATP）修饰以捕获醛类，Ag/Fe(CoNi)-LDH对醛类VOCs表现出优异的表面增强拉曼散射（SERS）性能，并实现了对10 ppb苯甲醛（BZA）的检测。b模式的增强和拉曼位移表明化学增强对SERS系统的贡献，因此该底物具有良好的均匀性。基于席夫碱反应的可逆性实现了SERS底物的循环利用。这些结果表明，Ag/FeCoNi-LDH在醛类痕量检测应用中具有广阔前景。
