Two-dimensional (2D) transition-metal dichalcogenides have become promising candidates for surface-enhanced Raman spectroscopy (SERS), but currently very few examples of detection of relevant molecules are available. Herein, we show the detection of the lipophilic disease marker β-sitosterol on few-layered MoTe₂ films. The chemical vapor deposition (CVD)-grown films are capable of nanomolar detection, exceeding the performance of alternative noble-metal surfaces. We confirm that the enhancement occurs through the chemical enhancement (CE) mechanism via formation of a surface–analyte complex, which leads to an enhancement factor of ≈10⁴, as confirmed by Fourier transform infrared (FTIR), UV–vis, and cyclic voltammetry (CV) analyses and density functional theory (DFT) calculations. Low values of signal deviation over a seven-layered MoTe₂ film confirms the homogeneity and reproducibility of the results in comparison to noble-metal substrate analogues. Furthermore, β-sitosterol detection within cell culture media, a minimal loss of signal over 50 days, and the opportunity for sensor regeneration suggest that MoTe₂ can become a promising new SERS platform for biosensing.

中文翻译：

---

二维碲化钼在生物相关分子SERS检测中的应用

二维（2D）过渡金属二卤化物已成为表面增强拉曼光谱（SERS）的有希望的候选物，但目前很少有检测相关分子的例子。本文中，我们显示了在几层MoTe ₂膜上检测亲脂性疾病标记β-谷固醇的方法。化学气相沉积（CVD）生长的薄膜能够进行纳摩尔检测，超过了其他贵金属表面的性能。我们可以确认，通过形成表面-分析物复合的，通过化学增强（CE）机制发生的增强，这导致的≈10增强因子⁴经傅里叶变换红外（FTIR），紫外可见光谱和循环伏安法（CV）分析以及密度泛函理论（DFT）计算得到证实。与贵金属基质类似物相比，七层MoTe ₂膜上的信号偏差值低，证实了结果的均质性和可重复性。此外，细胞培养基中的β-谷固醇检测，50天内信号损失最小以及传感器再生的机会表明，MoTe ₂可以成为有前途的新的生物传感SERS平台。