Si Kae Jye, Guo Pengzhen, Shi Qianqian, Cheng Wenlong
†Department of Chemical Engineering, Faculty of Engineering, Monash University, Clayton 3800, Victoria, Australia.
‡The Melbourne Centre for Nanofabrication, 151 Wellington Road, Clayton 3168, Victoria, Australia.
Anal Chem. 2015 May 19;87(10):5263-9. doi: 10.1021/acs.analchem.5b00328. Epub 2015 Apr 29.
We report on self-assembled nanocube-based plasmene nanosheets as new surface-enhanced Raman scattering (SERS) substrates toward direct identification of a trace amount of drugs sitting on topologically complex real-world surfaces. The uniform nanocube arrays (superlattices) led to low spatial SERS signal variances (∼2%). Unlike conventional SERS substrates which are based on rigid nanostructured metals, our plasmene nanosheets are mechanically soft and optically semitransparent, enabling conformal attachment to real-world solid surfaces such as banknotes for direct SERS identification of drugs. Our plasmene nanosheets were able to detect benzocaine overdose down to a parts-per-billion (ppb) level with an excellent linear relationship (R(2) > 0.99) between characteristic peak intensity and concentration. On banknote surfaces, a detection limit of ∼0.9 × 10(-6) g/cm(2) benzocaine could be achieved. Furthermore, a few other drugs could also be identified, even in their binary mixtures with our plasmene nanosheets. Our experimental results clearly show that our plasmene sheets represent a new class of unique SERS substrates, potentially serving as a versatile platform for real-world forensic drug identification.
我们报道了基于自组装纳米立方体的等离子体纳米片，作为新型表面增强拉曼散射（SERS）底物，用于直接识别拓扑复杂的真实世界表面上的痕量药物。均匀的纳米立方体阵列（超晶格）导致低空间SERS信号方差（约2%）。与基于刚性纳米结构金属的传统SERS底物不同，我们的等离子体纳米片机械性能柔软且光学上半透明，能够保形附着于真实世界的固体表面，如钞票，用于直接通过SERS识别药物。我们的等离子体纳米片能够检测到低至十亿分之一（ppb）水平的苯佐卡因过量，特征峰强度与浓度之间具有出色的线性关系（R(2) > 0.99）。在钞票表面，可实现约0.9×10(-6) g/cm(2)苯佐卡因的检测限。此外，即使是与我们的等离子体纳米片形成二元混合物的其他几种药物也能被识别。我们的实验结果清楚地表明，我们的等离子体片代表了一类新型独特的SERS底物，有可能作为真实世界法医药物识别的通用平台。
