新型粉末状荧光502熏显手印荧光波段研究

Selection of Fluorescence Band Using Novel Fluorescent Cyanoacrylate Powder for Latent Fingerprint Visualization

目的运用新型粉末状荧光502可一步显现非渗透性光滑客体表面潜手印。为了选择最佳的激发光源和滤光镜来观察熏显后荧光效果,本文对该粉末的荧光性能进行研究。方法使用荧光光谱仪对新型粉末状荧光502进行激发光谱和发射光谱的测试,进而选择合适的激发光源及滤光镜来进行观察和拍照。结果新型粉末状荧光502的光谱范围较宽,在波长为235nm^580nm范围内均可进行激发,具有广谱性,其中对波长在530nm附近的激发光具有最大峰值,即荧光强度最大,对450nm和360nm附近的光也具有很高的吸收峰值,斯托克斯偏移量为45nm。宏观验证实验表明,在仪器分析所得的范围内,显现出的手印效果均较好。结论运用该粉末在熏显手印后可以在紫外、紫光、蓝光、黄光、绿光范围内进行激发,斯托克斯偏移大,荧光亮度高,在观察荧光效果时能够很好的消除背景荧光的干扰,也便于选择滤光镜。手印荧光效果除了受到熏显物质荧光性能的影响外,还与激发光源的品质、滤光片的透过性能以及检材固有的发光特点、客体表面性质有关。

Objective This study aims to select the appropriate exciting light source and filter to visualize latent fingerprints on non-porous surface fumed with the novel fluorescent cyanoacrylate powder.Methods The appropriate light source and filter were selected by means of the fluorescence spectrometer along with both the excitation and emission spectrums decided.Results The analysis of new fluorescent cyanoacrylate powder by fluorescence spectroscopy showed that the excitation wavelength of light source was 235~580nm with the maximum peak at 530 nm where the fluorescent intensity was the biggest,and also quite strong absorbance peaks were obtained at 450 nm and 360 nm,with 45 nm Stokes shift.Verification experiments indicated that the effect of developing fingerprints was good in the range of 235~580nm.Conclusions The fingerprints fumed with the new fluorescent cyanoacrylate powder can be visualized under the light of UV,violet,blue,yellow,and green with the merits of large Stokes shift and high fluorescent intensity,easy to eliminate the interference of background fluorescence,and facilitative to select filters.The fingerprints can be visualized clearly with the fluorescence selected by comprehensive consideration of the above factors.Besides the property of fluorescent powder,the effect of developing fingerprint with fluorescence relies on the exciting light source,the filter,and the inherent luminescence characteristics of submitted exhibits and the conditions of exhibit surface.