Marshall Jamila S, Sita Madelyn L, Landers James P
Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA.
Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22903, USA.
Micromachines (Basel). 2021 Apr 15;12(4):442. doi: 10.3390/mi12040442.
To date, most research regarding amino acid detection and quantification in fingermarks relies on spectrometric methods. Herein, the Sakaguchi colorimetric test was adapted to a rotationally-driven microfluidic platform and used to detect and quantify arginine in fingermarks deposited by male and female donors. A red color indicates the presence of arginine in a given sample following the reaction, and the intensity of this color is linearly proportional to the concentration. Objective detection and quantification of arginine were accomplished using image analysis software (freeware) based on this colorimetric result. The mean concentrations obtained in a blind study were 96.4 ± 5.1 µM for samples from female donors and 55.3 ± 5.3 µM for samples from males. These were not statistically different from the literature values of 94.8 µM ± 12.9 µM for females ( 0.908) and 54.0 ± 12.6 µM for males ( 0.914), respectively (± SEM in all cases). Conversely, the experimental means from males and female samples were statistically different from each other ( 0.001). Objective differentiation between male and female fingermark deposits was achieved in a blind study with 93% accuracy. Additionally, the method was compatible both with samples lifted from common surfaces and with magnetically-powdered samples.
迄今为止，大多数关于指纹中氨基酸检测和定量的研究都依赖于光谱法。在此，坂口比色法被应用于一个旋转驱动的微流控平台，用于检测和定量男性和女性捐赠者留下的指纹中的精氨酸。反应后，红色表明给定样品中存在精氨酸，且该颜色的强度与浓度呈线性比例关系。基于此比色结果，使用图像分析软件（免费软件）实现了精氨酸的客观检测和定量。在一项盲测研究中，女性捐赠者样品的平均浓度为96.4±5.1μM，男性样品的平均浓度为55.3±5.3μM。这些结果与文献中女性的94.8μM±12.9μM（P = 0.908）和男性的54.0±12.6μM（P = 0.914）（所有情况下均为±标准误）无统计学差异。相反，男性和女性样品的实验平均值彼此有统计学差异（P = 0.001）。在一项盲测研究中，实现了对男性和女性指纹沉积物的客观区分，准确率为93%。此外，该方法与从常见表面提取的样品以及磁粉样品均兼容。
