Fabrication of SERS Swab for Direct Detection of Trace Explosives in Fingerprints
Fabrication of SERS Swab for Direct Detection of Trace Explosives in Fingerprints
复制标题
用于直接检测指纹中痕量爆炸物的 SERS 拭子的制作
DOI：
10.1021/am507424v
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发表时间：
2014-12-24
影响因子：
9.5
通讯作者：
Fan, Meikun
中科院分区：
文献类型：
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作者：
Gong, Zhengjun;Du, Hongjie;Fan, Meikun
拭子取样在表面污染分析中具有重要意义。通过自下而上的策略将棉签（棉Q-tip）成功地转化为表面增强拉曼散射（Sers）基底（Sers Q-tip），其中Ag纳米颗粒首先自组装到Q-tip上，然后原位生长。探讨了利用Sers Q-针尖直接拭子检测拉曼探针尼罗蓝A（NBA）和起爆药标记物2，4-二硝基甲苯（2，4-DNT）的能力。结果表明，在最佳条件下，可以用拭子法检测出NBA在玻璃表面上的谱图。2，4-DNT在玻璃表面的最低检测量仅为1.2 ng/cm（2）（总量为5 ng），比红外技术获得的类似表面分析灵敏度高2个数量级，甚至与离子迁移谱-质谱法获得的结果相当。最后对指纹上残留的2，4-DNT进行了分析。结果表明，用Sers Q-tip擦拭指纹后，27个指纹的2，4-DNT的Sers信号仍然可以被清晰地识别出来。我们相信这是第一个直接Sers擦拭测试爆炸物上的指纹在玻璃上。考虑到其相对较长的保质期（>30 d），当与便携式拉曼光谱仪结合使用时，Sers Q-尖端在未来的国土安全应用中可能会发现巨大的潜力。
Swab sampling is of great importance in surface contamination analysis. A cotton swab (cotton Q-tip) was successfully transformed into surface-enhanced Raman scattering (SERS) substrate (SERS Q-tip) through a bottom-up strategy, where Ag NPs were first self-assembled onto the Q-tip followed by in situ growing. The capability for direct swab detection of Raman probe Nile Blue A (NBA) and a primary explosive marker 2,4-dinitrotoluene (2,4-DNT) using the SERS Q-tip was explored. It was found that at optimum conditions, a femotogram of NBA on glass surface could be swab-detected. The lowest detectable amount for 2,4-DNT is only similar to 1.2 ng/cm(2) (total amount of 5 ng) on glass surface, 2 orders of magnitude more sensitive than similar surface analysis achieved with infrared technique, and comparable even with that obtained by ion mobility spectrometry-mass spectrometry. Finally, 2,4-DNT left on fingerprints was also analyzed. It was found that SERS signal of 2,4-DNT from 27th fingerprint after touching 2,4-DNT powder can still be clearly identified by swabbing with the SERS Q-tip. We believe this is the first direct SERS swabbing test of explosives on fingerprint on glass. Considering its relative long shelf life (>30 d), the SERS Q-tip may find great potential in future homeland security applications when combined with portable Raman spectrometers.