Abstract: Objective To establish a surface-enhanced Raman spectroscopy（SERS） method for the accurate discrimination and rapid identification of ballpoint pen ink. Methods Nano Ag colloid was selected as the enhancing reagent and applied on the ink entries of 55 black ballpoint pens collected from domestic market. The ink samples were tested with three excitation wavelengths, i.e. 785 nm, 633 nm and 514 nm. The data collected with each wavelength was analyzed comprehensively. Results The SERS spectra effectively presented the differences between different brands of ballpoint pen ink. Compared with the spectrum acquired by normal Raman spectroscopy, the peak signals after enhancement were much higher. Thus, the differences between similar inks were more apparent and can be easily classified. Besides, more information were obtained by combining the spectral information of three wavelengths. Conclusion This method can effectively discriminate different brands of black ballpoint pen ink, which provides a new approach for the rapid identification of ink components in forensic science.

Key words:  surface enhancement Raman spectroscopy（SERS）, ballpoint pen, classification

摘要： 目的 建立圆珠笔油墨的表面增强拉曼光谱分析方法，实现更加有效的圆珠笔样品种类区分。方法 选用纳米银胶体作为增强试剂，在785、633、514 nm 3种激发光波长下，分析检测市场上55支黑色圆珠笔的表面增强拉曼光谱，并通过将各激发光波长下的数据相结合来综合分析种类区分信息。结果 根据表面增强拉曼光谱图可有效区分出不同品牌圆珠笔油墨之间的差异。与增强前的拉曼光谱相比，增强之后的谱峰信号更强，在进行种类区分时更具说服力。785、633、514 nm 3种激发光波长的谱图信息相结合可获取更多有效的区分信息。结论 该方法能够有效鉴别不同品牌同一颜色的圆珠笔油墨，为司法鉴定中油墨成分的快速鉴别提供新思路。

关键词: 表面增强拉曼, 圆珠笔, 种类区分