Verma Ashwani Kumar, Singh Jaspal, Nguyen-Tri Phuong
Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
Laboratory of Advanced Materials for Energy and Environment, Université Du Québec à Trois-Rivières (UQTR), 3351, Boul. des Forges, C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada.
ACS Appl Mater Interfaces. 2024 Feb 28;16(8):10969-10983. doi: 10.1021/acsami.3c17303. Epub 2024 Feb 14.
The interaction of graphene with metals initiates charge-transfer interaction-induced chemical enhancements, which critically depend on the doping effect from deposited metallic configurations. In this paper, we have explored the gold nanoparticle-decorated monolayer graphene nanosheets for the large graphene-induced Raman enhancement of adsorbed analytes, indicating the surface-enhanced Raman spectroscopy (SERS) capabilities of metal-doped graphene (G-SERS). Here, the systematically sputtered Au thickness optimization procedure revealed noticeable modifications in the graphene Raman spectra and photoluminescence (PL) background quenching, which indicated favorable charge transfer through n-type doping of chemical vapor deposition-grown graphene nanosheets. The highly consistent, individually distributed morphology of the gold nanoislands over graphene nanosheets depicted a reproducibly uniform G-SERS signal with excellent relative standard deviation values (<5%), resulting in the strongest Raman intensity enhancement factors of ∼10 (MB) (methylene blue) and 10 (DPA) (2,6-pyridinedicarboxylic acid) composed of the weakest PL background. The combined charge-transfer-induced chemical enhancement and electromagnetic enhancement from individual Au nanoislands result in a lowering of detectability down to 10 M (MB) and 10 M (DPA) concentrations with efficient time-dependent signal stability. Additionally, the GAu demonstrated its effective (∼94.4%) photocatalytic degradation capabilities by decomposing MB dye molecules from a concentration of 1 μM to 2.52 fM within 60 min. Therefore, the prominent charge-transfer contribution through controlled Au decoration over graphene nanosheets provides a potential strategy for fabricating superior SERS sensors and photocatalysts exhibiting adequate signal consistency, stability, and photodegradation efficiency through overcoming the limitations of the traditional sensing platforms.
石墨烯与金属的相互作用引发了电荷转移相互作用诱导的化学增强，这主要取决于沉积金属构型的掺杂效应。在本文中，我们探索了用金纳米颗粒修饰的单层石墨烯纳米片，用于实现大的石墨烯诱导的吸附分析物的拉曼增强，这表明了金属掺杂石墨烯的表面增强拉曼光谱（G-SERS）能力。在此，通过系统溅射优化金厚度的过程揭示了石墨烯拉曼光谱的显著变化以及光致发光（PL）背景猝灭，这表明通过化学气相沉积生长的石墨烯纳米片的n型掺杂实现了有利的电荷转移。金纳米岛在石墨烯纳米片上高度一致、单独分布的形态描绘了具有优异相对标准偏差值（<5%）的可重复均匀的G-SERS信号，从而产生了约10（亚甲基蓝）和10（2,6-吡啶二甲酸）的最强拉曼强度增强因子，其PL背景最弱。单个金纳米岛的电荷转移诱导的化学增强和电磁增强共同作用，使得检测限降低到10 M（亚甲基蓝）和10 M（2,6-吡啶二甲酸）浓度，同时具有高效的时间依赖性信号稳定性。此外，GAu通过在60分钟内将1 μM浓度的亚甲基蓝染料分子分解至2.52 fM，展示了其有效的（约94.4%）光催化降解能力。因此，通过在石墨烯纳米片上进行可控的金修饰而产生的显著电荷转移贡献，为制造卓越的SERS传感器和光催化剂提供了一种潜在策略，通过克服传统传感平台的局限性，实现足够的信号一致性、稳定性和光降解效率。
