纳米二氧化钛荧光粉末显现潜在手印研究

目的使用荧光染料包覆纳米二氧化钛颗粒,制备具有荧光效果的纳米二氧化钛粉末材料,并探索应用纳米二氧化钛荧光粉末显现潜在手印的方法。方法使用实验室合成的二酰亚胺染料与纳米二氧化钛微粒按照一定质量比混合制备形成荧光粉末,通过扫描电子显微镜对其进行表征,观察颗粒结构特征。在玻璃、瓷砖、透明塑料片、彩色塑料包装、易拉罐5类非渗透性客体上捺印手印,观察纳米二氧化钛荧光粉末对不同非渗透性客体上新鲜潜手印的显现效果。分别在5种客体上制作遗留时间为1、4、7、15d的手印样本,考察遗留时间对纳米二氧化钛荧光粉末显现自然陈旧手印效果的影响。将新鲜手印置于标准大气压100℃条件下分别加热1~72h,使用纳米二氧化钛荧光粉末显现,考察其对高温老化手印的显现效果。结果纳米二氧化钛荧光粉末为粒径100~200nm的圆形颗粒;在蓝绿光激发下可发出较强的荧光,能显现多种非渗透性客体上的新鲜手印,与背景反差明显并且能显著降低复杂背景对手印纹线的影响;显出新鲜手印中80%以上具有鉴定条件。纳米二氧化钛荧光粉末对遗留15d以内的陈旧手印仍具有较好的显现效果。100℃高温环境对手印显现效果没有明显影响。结论纳米二氧化钛荧光粉末经济、环保,显现操作简单,易于推广。     

利用CdSe巯基乙酸溶液显现水浸客体表面潜手印

目的研究水浸客体表面潜指纹的显现方法;方法利用CdSe巯基乙酸溶液显现被水浸泡过的黄色封箱胶带、黑色塑料袋、玻璃等常见非渗透性客体上的潜手印,讨论影响水浸非渗透性客体上潜手印显现效果的各种因素,并与传统方法进行比较,初步探讨了CdSe巯基乙酸溶液显现水浸非渗透性客体表面潜手印的方法;结果使用巯基乙酸包覆CdSe纳米复合材料显现潜在手印,使每分子纳米复合材料外表包覆足够数量的羧基,则可以提高它同手印残留物的结合能力,从而得到更高清晰度、更高分辨率的手印显像;结论巯基乙酸包覆CdSe纳米复合材料可以很好的显现水浸塑料、胶带等表面潜指纹。     

一种改进的碘熏法-碘锌手印显现法

目的为解决传统碘熏法显出手印容易褪色、固定困难等问题。方法提出了一种改进的碘熏法-碘锌手印显现法，实验了不同反应物配比、不同客体材质对显现效果的影响；与常规碘熏法进行了对比实验；并考察了碘锌法显出手印的稳定性。结果碘锌手印显现法可以用于常见渗透性及非渗透性客体上新鲜汗潜手印的显现。该方法不必外加热源，携带、存储和应用更加便利；该方法显出的指纹纹线保存时间与传统碘熏法相比明显延长。结论碘锌手印显现法是一种高效、实用的手印显现方法。     

真空镀膜与“502”熏显法显现非渗透性客体上汗潜手印的比较研究

目的探索真空镀膜手印显现技术,提高现场潜在手印显现率。方法通过真空镀膜与＂502＂熏显法显现常见非渗透性客体上汗潜手印的对比实验,比较二者显现效果优劣。结果真空镀膜法对于显现常见非渗透性客体上的新鲜和陈旧汗潜手印都有着明显的优势。结论真空镀膜是一种更为灵敏的非渗透性客体手印显现方法,是现有手印显现方法的重要补充。     

新型荧光502粉末显现手印技术的改进研究

目的 对新型粉末状荧光502显现手印的方法进行进一步探索和完善,确保其高效便捷和科学准确.方法 将PolyCyano UV粉末加热至230℃使其升华,待该粉末在手印纹线上聚合附着后用长波紫外线或蓝光激发拍照,并与初步研究结果相比较.结果 大部分非渗透性光滑客体表面上的汗潜手印均有很好的显现效果.结论 该方法使显现流程更加高效便捷、显现时间短、无需二次染色增强、不破坏生物检材,适合推广使用.     

浅色调湿粉显现手印方法的研究

目的探索新的手印显现方法,祛除传统手印显现方法对使用者的健康危害;方法用浅色调湿粉采用不同操作对不同客体表面手印、不同物质手印及不同遗留时间手印进行显现,通过显现效果的比较,得出湿粉显现手印的适用范围、最佳操作方法及其显现效果;结果显出的手印清晰、流畅,与背景反差强;结论该方法适用于光滑非渗透性客体表面及潮湿或粘性表面的汗潜、油潜、蛋白手印的显现,使用方便有效。     

荧光黄湿粉显现手印方法的初步研究

目的研发一种具有荧光特性的黄湿粉,以提取遗留在不同客体上的不同种类的手印。方法在100mL温水中加入适量的表面活性剂,溶解后加入100g荧光黄颜料,选用不同种类客体及不同种类物质手印进行显现实验,比较显现效果;结果遗留在光滑非渗透性客体及半渗透性客体表面的汗潜、油潜手印,显出的手印纹线流畅、反差强、荧光强;结论荧光黄湿粉可适用于光滑非渗透性客体及半渗透性客体表面新鲜或较新鲜汗潜手印、油潜手印及血潜手印的显现。     

深、浅色小颗粒悬浮液显现汗潜手印的比较研究

实验采用氧化锌、二氧化钛、二硫化钼和四氧化三铁粉末,按照不同配方配制了4种悬浮液,对小颗粒法显现汗潜手印的试剂浓度、操作方法、对陈旧手印的适用性及小颗粒悬浮液的放置时间、对深色浅色客体、对光滑非渗透性客体、半渗透性客体和个别渗透性客体上的手印显现进行了研究和探讨。     

双亲性二氧化硅纳米悬浮液显现手印初探

目的 考查制备的双亲性二氧化硅纳米粒子在配制成悬浮液后对非渗透性客体上手印显现的能力。方法 通过调整溶剂类型、二氧化硅纳米粒子浓度、表面活性剂种类、溶液pH值等因素,探索二氧化硅纳米粒子悬浮液显现手印的最佳方法,并应用于手印显现和效果比较。结果 利用优化后的悬浮液浸显一些非渗透性客体表面的汗潜手印,显出的手印纹线流畅、细腻,细节特征清晰,反差明显,与传统的显现方法比较,此法具有明显优势。结论 研究表明,纳米二氧化硅悬浮液是显现手印的一种有效、简便和经济的方法,具有很好的应用前景。     

酸性黄显现非渗透性客体上血潜手印初步探究

目的建立一种酸性黄显现非渗透性客体上血潜手印的方法。方法制备白色瓷砖、黑色塑料袋、黑色瓷瓶、易拉罐侧面、深色铁质茶叶盒等为客体的捺印手印,配置以酸性黄作为主要成分的染色剂,对其进行固定、染色、漂洗,在多波段光源下观察。结果在440nm激发光源条件下,通过橙色护目镜观察有很强的黄色荧光特征。结论酸性黄显现法具有操作简单、显现效果明显、能排除深色背景干扰的特点,容易推广使用。     

PAMAM G7.0的制备及在非渗透性表面手印显现中的应用

目的探索一种非渗透性表面手印显现的新方法。方法根据现有方法合成第七代聚酰胺-胺（PAMAM G7.0）树形分子材料,并使用荧光光谱法对产物进行荧光测试;将合成材料对多种客体表面、不同遗留时间的手印进行显现,并将显现结果与粉末法和传统的荧光染料法进行比对。结果实验表明该荧光材料在365nm光激发下可以发出较强的可见荧光;与粉末法和传统的荧光染料法相比,PAMAM G7.0可以同手印残留物进行高选择性结合,手印纹线与背景之间的反差大。结论PAMAMG7.0可以有效地显出非渗透性客体表面的手印。     

胺端基型CdS／PAMAM潜在显现指印的应用

目的探索一种新型纳米荧光材料的制备方法及其在潜在指印显现方面的应用前景。方法以聚酰胺-胺（PAMAM）树形分子为模板，原位合成CdS纳米簇。并使用荧光光谱法对产物进行表征：应用这种新型荧光材料对多种客体表面、不同陈旧程度的潜在指印进行显现．并将显现结果与传统荧光染料进行比对。结果该荧光材料在365nm紫外光激发下可以发出很强的可见荧光：与传统的荧光染料相比。-NH2端基型CdS／PA—MAM可以同指印残留物进行靶向结合．其荧光强度高、背景干扰小，指印纹线与客体反差大。结论-NH2端基型CdS／PAMAM可以有效地显出非渗透性客体表面的潜在指EP。     

低温荧光法显现汗潜指纹初探

目的　探索汗潜指纹显现的新方法。方法　利用低温荧光摄影方法加强指纹沉积物的固有荧光强度 ,来提高汗潜指纹显现的成功率。结果　在 4 1 5nm波段激发下用黄滤色镜拍摄指纹的显现效果最好。结论　低温荧光法是一种有效的潜指纹显现的技术手段     

Photoluminescence of blood by acidic hydrogen peroxide—A preliminary test

In this study, the authors found that treating blood with 1 M HCl and 2% (w/v) 5-sulfosalicylic acid (SSA) in 1% (v/v) hydrogen peroxide mixture can produce photoluminescence of blood. SSA was added as a blood fixer. The photoluminescence was induced by irradiation of a forensic light source at 505 nm, which was detected using a 550 nm barrier filter. In this experiment, various level of acid and hydrogen peroxide were tested to find the optimal formulation of reagents, spot tests were conducted with diluted blood to test the sensitivity of this reagent, and impressions in blood left on porous/nonporous surfaces were enhanced. The sensitivity of this solution was slightly lower than Bluestar and was similar to leucocrystal violet or leucomalachite green on both porous/non-porous surfaces. The photoluminescence of blood treated with this reagent has been observed over 2 months. Using this reagent, it was possible to observe fingermarks or footwear impressions in blood on a black porous/non-porous surface. Through this, it was found that using this reagent could enhance bloodstains regardless of the porosity or color of the surface.     

Comparison of operational DNA recovery methods: Swabs versus tapelifts

It is routine among many jurisdictions to recover DNA using tapelifts on porous substrates (e.g. clothing) and swabs on non-porous substrates (e.g. tool handles). Here, we examine this by comparing the efficiency of the NSW jurisdiction’s specific swabbing and tapelift techniques on a range of porous and non-porous substrates. To test DNA recovery efficiency, 30 μl aliquots of 1:50 and 1:100 saliva dilutions were deposited onto the substrates, left to dry overnight, recovered, extracted, quantified and a subset profiled. Tapelifts recovered more DNA and DNA profiles with more detectable alleles than swabs for both saliva dilutions on porous substrates. For non-porous substrates, similar DNA quantities and profiles were generally recovered with both methods for both saliva dilutions. These data underpin current practices to recover DNA using tapelifts for porous substrates and swabs for non-porous substrates. These data also revealed severe degradation of DNA recovered from brass, supporting the on-going need to improve DNA recovery and analysis methods for brass substrates.     

ZnS和ZnS:Cu无机紫外荧光材料的制备及其在汗潜手印显现中的应用

目的制备荧光强度高、客体适用性广、显现效果优良且合成方法简单的ZnS及ZnS:Cu无机紫外荧光材料,并将其用于汗潜手印的显现。方法通过一步溶液反应共沉淀法制备ZnS无机紫外荧光材料,并在ZnS材料中加入Cu^2+得到ZnS:Cu以改善荧光性质,将其应用于普通客体(白色捺印纸、载玻片、铁架台、乳白色花纹瓷砖表面、磨砂化学实验台面、不锈钢表面)和复杂客体(拼色花纹瓷砖、农夫山泉塑料标签和杂志封面铜版纸)上汗潜手印的显现,并与传统荧光粉末显现效果进行对比。结果ZnS材料具有荧光性,并且在ZnS材料中掺杂Cu^2+后得到的ZnS:Cu材料荧光强度增强,荧光光谱范围变广,稳定性提升。显现汗潜手印时,适用客体范围更广,并且可通过调节激发光的波长呈现不同的显现效果。结论通过在无机荧光材料ZnS中掺杂Cu^2+可改善材料的荧光范围,从而得到适用于不同客体上汗潜手印显现且效果更好的ZnS:Cu无机紫外荧光材料。     

Fluorescence of 1,2‐Indanedione with Amino Acids Present in the Fingerprint Residue: Application in Gender Determination

1,2‐indanedione is used for latent fingerprint visualization on porous surfaces. In this paper, fluorescence spectra of 1,2‐indanedione after reacting with 21 individual amino acids present in latent fingerprints residue were measured in water‐methanol solutions. The fluorescence intensity depends on the amino acid used, while the fluorescence peak does not change much. The concentration of amino acids in fingerprint residue in females is almost the double of their concentration in males. This property combined with fluorescence of 1,2‐indanedione‐amino acids compounds is used for gender determination, by comparing the fluorescence intensity peaks in the same experimental conditions. In this preliminary study, the fluorescence signal from the samples representing females was almost two times the signal for samples representing males. In addition to the reduction by almost 50% of the number of suspects in a criminal research case, these results could be helpful in gaining some knowledge about the papillary residue composition.     

The effect of mark enhancement techniques on the presumptive and confirmatory tests for blood

An investigation into the effects of physical and chemical enhancement on subsequent presumptive and confirmatory tests for human blood is presented. Human blood was deposited onto porous (white 80 gsm paper and brown envelope) and non-porous (tile and linoleum) substrates in a depletion series (30 depletions on non-porous and 20 on porous) and subjected to three ageing periods; 1, 7 and 28?days. A number of enhancement techniques were tested [fluorescence, black magnetic powder (BMP), iron-oxide black powder suspension (PS), cyanoacrylate (CA) fuming, acid violet 17 (AV17), acid yellow 7 (AY7), ninhydrin, DFO and Bluestar Forensic Magnum (BFM) luminol] to evaluate their potential effects on subsequent presumptive and confirmatory tests. AV17 and Bluestar provided the best enhancement and fully enhanced all depletions in the series. The sensitivity of the Kastle-Meyer (KM) (presumptive), Takayama and RSID-Blood tests (confirmatory) was initially investigated to determine the range of detectable depletions. The KM test detected all depletions, whereas the Takayama test detected up to depletion 6 and RSID-Blood detected up to depletion 20 (paper), 10 (envelope), 15 (tile) and 9 (lino). The abilities of these tests to detect blood after enhancement were then observed.A number of techniques resulted in little to no effect on any of the blood tests, whereas adverse effects were observed for others. Ninhydrin and CA fuming caused weak but instantaneous positive KM results whereas methanol-based AV17 and AY7 delayed the reaction by as much as 1?min. The Takayama test was not very sensitive, therefore, its performance was easily affected by enhancement and negative results were often observed. RSID-Blood tests were largely unaffected by chemical enhancement although a drop in positive results was observed for some of the techniques when compared to positive controls.Using a standard procedure for DNA extraction, all the tested blood samples (before and after enhancement) gave a detectable quantity of DNA and were successfully profiled. Out of the 45 samples processed for DNA profiling, 41 gave full profiles, while the remaining showed allele drop out in one or two loci.