Name: fluorescent paper strips for the detection of diesel adulteration with smartphone read-out
Uploaded: 2018-11-09T12:30:00
Description: Watch this Scientific Journal Video about Fluorescent Paper Strips for the Detection of Diesel Adulteration with Smartphone Read-out at JoVE.com

作者希望通过重点领域的分析科学: https://www.bam.de/Navigation/EN/Topics/Analytical-Sciences/Rapid-Oil-Test/rapid-oil-test.html, 感谢 bam 提供资金。

1. 荧光染料 (图 1 a)
<ol><li>购买市售的4-dns 和4-dns-oh。 注: 4-dns-cooh 在商业上无法买到, 是由4-dns-oh 制成的, 如下文所述。</li>
	<li>放置50毫克 (0.16 mmol) 的 2 [ethyl[4-[2-(4-硝基苯) 苯] 氨基] 乙醇, 2 毫克 (0.016 mmol) 4-二甲基氨基吡啶和19.2 毫克 (0.16 mmol) 琥珀酸酐在10毫升圆形底部瓶。</li>
	<li>在氩气氛下溶解干二氯甲烷中的2毫升中的试剂。</li>
	<li>加入 11.6μl (0.08 mmol) 三乙胺, 让混合物反应20小时。</li>
	<...

<ol>
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Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smartphone-based+Chemistry+Instrumentation:+Digitization+of+Colorimetric+Measurements.">Smartphone-based Chemistry Instrumentation: Digitization of Colorimetric Measurements.</a> Bulletin of the Korean Chemical Society. 33 (2), 549-552 (2012).</li><li>Roda, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smartphone-based+biosensors:+A+critical+review+and+perspectives.">Smartphone-based biosensors: A critical review and perspectives.</a> TrAC Trends in Analytical Chemistry. 79, 317-325 (2016).</li><li>McCracken, K. E., Yoon, J. -. 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以分子转子染料为基础, 在柴油及其不同与煤油共混物的范围内, 对粘度敏感, 利用荧光探针获得了检测柴油掺假的简单有效的试纸。不同柴油/煤油共混物中的 4-dns 在550纳米的排放强度与煤油比例增加时粘度降低有关。在24°c 的温度下, 观察到高达55% 的非线性荧光淬火, 可用于100% 与煤油一起掺假, 从而能够可靠地定量掺假, 标准偏差较低, 为1.70。
然而, 由于疏水性染料与疏水?...

燃料掺假在世界许多不同地区是一个严重的问题, 这仅仅是因为燃料作为一种能源具有巨大的相关性。在掺假燃料上运行发动机会降低其性能, 导致较早的发动机故障, 并造成环境污染1。如果柴油掺入通常含有较高含量的硫 2, 3 的煤油,则会产生更多的 sox 排放。虽然这个问题存在了几十年, 但在其来源地发现这种犯罪活动的可持续燃料管理仍然很少, 因为对燃料掺假的简单和可靠的检测基本上缺乏4。尽管在过去几十年中在实验室矿物油分析方面取得了重大进展, 但现场测量的方法仍然很少。最近设计了在实验室外使用的各种方法, 使用光纤8、场效应晶体管9或机械变色材料10。虽然它们克服了传统方法的一些缺点, 但仍然严重缺乏可靠、方便用户和可移植的方法。基于分子转子的荧光粘度探针是一个有趣的替代品11,12, 因为矿物油是由各种碳氢化合物组成的, 这些碳氢化合物在链长和旋回性上各不相同, 而且通常反映在不同的粘度。由于燃料是复杂的混合物, 没有特定的铅化合物作为示踪剂, 测量的宏观性质的变化, 如粘度或极性似乎是非常有希望的。后者可以通过荧光分子转子来解决, 荧光量子产量取决于环境粘度。光激发后, 失活通常涉及扭曲的分子内电荷转移 (tiict) 状态, 其种群是由其周围微环境的粘度决定的 13.高粘度溶剂阻碍分子转子采用 tict 状态, 从而产生明亮的排放。在低粘性溶剂中, 转子可以更好地进入 tict 状态, 加速非辐射衰变, 从而抑制荧光。在27°c 时, 将粘度为 1.64 mm 2 s*-1的煤油添加到柴油中, 在1d、24.0、en 950 级的温度下, 其粘度分别为1.0-2.4、1.9-4.1、2.0-4.5 或 5.5-24-44.0 毫米 *-1 4d14、15、16降低了混合物的运动粘度, 并有可能导致分子转子探针荧光的比例淬火。4-二甲基氨基-4-硝基雌二苯醚 (4-dns) 的家族似乎对我们最有希望, 因为它们在 0.74-70.6 mm2的运动粘度范围内具有很强的荧光变化。这个范围与煤油和柴油的已知值很匹配。
因此, 我们探索了4dns 的能力, 2-[ethyl[4-[4-硝基苯) 苯] 氨基] 乙醇 (4dnsoh) 和 (e)-4-(2-(ethyl(4-(4-----(4-亚硝基苯乙烯) 苯基) 氨基)-4-氧丁烷酸 (4dsooh) 表明其粘度柴油煤油混合物通过其荧光, 取决于分子内的旋转, 并最终产生了一个快速测试柴油掺假与煤油。一次性测试易于使用, 精确、可靠、经济高效且尺寸小。研究了探针作为固体载体对滤纸的吸附, 并利用嵌入式智能手机荧光读取器进行了分析。如今, 无处不在的智能手机配备了高质量的摄像机, 使颜色和荧光等光学变化的检测变得简单, 并为强大的现场分析铺平了道路。我们在这里证明, 测量用智能手机吸附在纸带上的荧光探针的排放, 可以用可靠的方式检测燃烧燃料上的欺诈行为17。

<table>
	<tbody>
		<tr>
			<td>4-dimethylamino-4-nitrostilbene (CAS Number: 2844-15-7)</td>
			<td>Sigma-Aldrich</td>
			<td>39255</td>
			<td>4-DNS Dye</td>
		</tr>
		<tr>
			<td>2-[ethyl[4-[2-(4-nitrophenyl)ethenyl]phenyl]amino]ethanol (CAS Number: 122258-56-4)</td>
			<td>Sigma-Aldrich</td>
			<td>518565</td>
			<td>4-DNS-OH Dye</td>
		</tr>
		<tr>
			<td>Whatman&#160;qualitative filter paper, Grade 1</td>
			<td>Sigma-Aldrich</td>
			<td>Z274852</td>
			<td>Test strips support</td>
		</tr>
		<tr>
			<td>Whatman&#160;application specific filter, activated carbon loaded paper, Grade 72</td>
			<td>Sigma-Aldrich</td>
			<td>WHA1872047</td>
			<td>Fuel pre-treatment filters</td>
		</tr>
		<tr>
			<td>Pall reusable in-line filter holders stainless steel, diam. 47&#160;mm</td>
			<td>Sigma-Aldrich</td>
			<td>Z268453&#160;</td>
			<td>Holder pre-treatment filters</td>
		</tr>
		<tr>
			<td>(3-Aminopropyl)triethoxysilane</td>
			<td>Sigma-Aldrich</td>
			<td>919-30-2</td>
			<td>APTES</td>
		</tr>
		<tr>
			<td>4-(Dimethylamino)pyridine</td>
			<td>Sigma-Aldrich</td>
			<td>1122-58-3</td>
			<td>DMAP</td>
		</tr>
		<tr>
			<td>Succinic anhydride</td>
			<td>Sigma-Aldrich</td>
			<td>108-30-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Triethylamine</td>
			<td>Sigma-Aldrich</td>
			<td>121-44-8</td>
			<td>Et3N</td>
		</tr>
		<tr>
			<td>N,N&#39;-dicyclohexylcarbodiimide&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>538-75-0</td>
			<td>DCC</td>
		</tr>
		<tr>
			<td>Stuart Tube Rotators</td>
			<td>Cole-Parmer</td>
			<td>SB3</td>
			<td>Rotator</td>
		</tr>
		<tr>
			<td>FreeCAD</td>
			<td>freecadweb.org</td>
			<td>-</td>
			<td>Freeware - 3D design</td>
		</tr>
		<tr>
			<td>Ultimaker Cura</td>
			<td>Ultimaker</td>
			<td>-</td>
			<td>Freeware - 3D printing</td>
		</tr>
		<tr>
			<td>Android Studio</td>
			<td>Google</td>
			<td>-</td>
			<td>Freeware - App programming</td>
		</tr>
		<tr>
			<td>Renkforce SuperSoft OTG-Mirror Micro-USB Cable 0,15 m</td>
			<td>Conrad.de</td>
			<td>1359890&#160;- 62</td>
			<td>Smartphone setup electronic part</td>
		</tr>
		<tr>
			<td>Black Cord Switch 1 x Off / On</td>
			<td>Conrad.de</td>
			<td>1371835&#160;- 62</td>
			<td>Smartphone setup electronic part</td>
		</tr>
		<tr>
			<td>Carbon Film Resistor 100 &#937;</td>
			<td>Conrad.de</td>
			<td>1417639&#160;- 62</td>
			<td>Smartphone setup electronic part</td>
		</tr>
		<tr>
			<td>492 nm blocking edge BrightLine&#160;short-pass filter</td>
			<td>Semrock</td>
			<td>FF01-492/SP-25</td>
			<td>Filter excitation</td>
		</tr>
		<tr>
			<td>550/49&#160;nm BrightLine single-band bandpass filter</td>
			<td>Semrock</td>
			<td>FF01-550/49-25</td>
			<td>Filter emission</td>
		</tr>
		<tr>
			<td>&#216;1/2&#34; Unmounted N-BK7 Ground Glass Diffuser, 220 Grit</td>
			<td>Thorlabs</td>
			<td>DG05-220</td>
			<td>Diffuser excitation</td>
		</tr>
		<tr>
			<td>LED 465 nm, 9 cd, 20 mA, &#177;15&#176;, 5 mm clear epoxy</td>
			<td>Roithner</td>
			<td>RLS-B465</td>
			<td>LED excitation</td>
		</tr>
	</tbody>
</table>

fluorescent paper strips for the detection of diesel adulteration with smartphone read-out

研究了三种荧光分子转子的 4-二甲基氨基-4-硝基雌二 (4-dns) 作为粘度探针的潜在用途, 以表明在二丝/煤油共混物中煤油的含量, 这是一种广泛的掺假燃料活性。在低粘度溶剂中, 染料通过所谓的扭曲分子内电荷转移状态迅速失活, 有效地淬火荧光。对柴油/煤油共混物的测定表明, 在柴油/煤油共混物中, 荧光的减少与黏性较低的煤油分数的增加有很好的线性关系。纤维素纸中羟基衍生物4-dns-oh 的固定化产生了保持荧光指示器行为的试纸。结合基于智能手机和控制应用程序的读卡器的条带, 可以创建一个简单的现场测试。该方法能可靠地检测柴油中煤油的含量在 7% ~ 100% 之间, 优于现有的柴油掺假标准方法。

两种商用染料4-dns 和4-dns-oh 的三种结构和合成染料4-dns-cooh 含有用供体 (-nr2) 和两端的受体 (-no2) 基团取代的稳定值核心元素, 中心双键构成所谓的 "分子转子" 的铰链 (图 1a)。结构在氨基取代模式与短烷基为 4-dns, 两个稍长的组, 包括酒精基团为4-dns-oh 和酯链接器终止与羧酸功能为 4-dns-cooh (图 1 a)。
<p class="jove_...

Watch this Scientific Journal Video about Fluorescent Paper Strips for the Detection of Diesel Adulteration with Smartphone Read-out at JoVE.com

Fluorescent Paper Strips for the Detection of Diesel Adulteration with Smartphone Read-out

用智能手机读数检测柴油掺假的荧光纸片

在这里, 我们提出了一个协议, 以检测柴油与煤油的掺假使用测试条涂层荧光粘度探头与智能手机的分析系统。

Three fluorescent molecular rotors of 4-dimethylamino-4-nitrostilbene (4-DNS) were investigated for their potential use as viscosity probes to indicate ...

这些油尺检测结合了荧光粘度探针和智能手机读出器的总体目标是检测柴油掺假与煤油，并检测此类欺诈和避免经济损失。这种方法可以帮助资源有限的国家的用户根据世卫组织的保证需求进行快速测试。虽然该方法为检测燃油掺假提供了一种新工具，但也可用于其他现场测量应用，例如爆炸物检测或水分析。准备参考染料和染料的一毫摩尔溶液4-DNS，4-DNS-OH和4-DNS-COOH在甲苯，如文本协议中所述。从滤纸中切割 30 到 5 毫米的纤维素条。将其中大约 50 条条放在可密封的五毫升小瓶中，以及 4.5 毫升所需的染料溶液。在转速为 30 rpm 时，用垂直旋转器摇动小瓶内的条带 20 分钟。然后将甲苯溶液从小瓶中倒出。立即填充四毫升环氧烷，并在转速 30 时旋转一分钟，以洗去多余的染料。重复此洗涤操作三次。洗涤后，在室温下将获得的测试条在室温下干燥 10 分钟，然后按照文本协议中所述进行样品预处理。购买标准 5 毫米环氧树脂 LED，460 纳米，100 欧姆电阻器，以及带开机开关和微型 USB 端口的 USB 在线电缆。切断位于运行侧的 USB 电缆，以隔离为正五伏电源的红线和与地面对应的黑色导线。现在，切断 USB 电缆的黑色导线，焊接开关背面的 100 欧姆电阻器。将 LED 阳极焊接到正五伏红线，将 LED 阴极焊接到接地黑线。为 LED 和摄像机购买扩散器和两个滤波器，通常是用于激励通道的短通滤波器和用于发射收集的带通滤波器。3D 打印适合智能手机的智能手机外壳，并集成了由文本协议中描述的黑色室组成的不同光学部件。此外，3D 打印条形支架以容纳参考和测试条。通过放置 LED、扩散器和滤光片以 60 度的角度照亮纸条来实现激励通道。将滤镜放在智能手机 CMOS 摄像机前面，实现读取通道。单击软件窗口右上角的菜单按钮，从软件内存中选择足够的校准文件。用钳子按住测试条，将测试条浸入柴油样品中几秒钟。用干燥纸填充以去除多余的燃油。将测试条放在参考条旁边的带子架内，然后将支架引入智能手机外壳。然后，在智能手机的屏幕上立即显示条带荧光的图像。按拍摄按钮记录测试和参考条的荧光强度。掺假程度由内部算法立即计算并在屏幕上显示。为了获得用荧光分子转子编码的测试条作为粘度探针，在纸上编码了三种类型的染料。一个候选者，4-DNS-OH，被发现是检测柴油掺假与煤油最合适的探头。将条状插入 3D 打印外壳后，使用智能手机摄像头确定条带的荧光。外壳集成了条形支架和所有必要的光学元件，例如由智能手机 USB 端口、滤镜和扩散器直接供电的 LED。检测过程尽可能简单，只需几步，浸渍，将条带放在支架中，启动 LED，并将支架定位在箱子中，然后进行测量和分析。分析软件对与条带对应的预定义空间区域中像素的所有 RGB 值进行平均，并将其转换为荧光强度。一旦掌握了，这项技术可以在一两分钟内完成。观看此视频后，您应该清楚地了解这种具有成本效益、精确和快速的燃油掺假方法应如何工作。这也是有趣的取证解决方案，例如，如果未经培训的权威人员或消费者发现欺诈行为。在尝试此过程时，必须记住选择足够的校准文件，特别是在处理不同等级的任何柴油样品时，因为它们可以在条带上进行专门交互。按照此程序，可以执行其他参考或实验室方法，如 GC-FID，以验证在筛查过程中现场观察到的阳性结果。因此，这项技术可以为其他研究人员将荧光油尺检测与嵌入式智能手机读出系统相结合铺平道路，为现场检测（如水中污染物或其他取证应用）提供有价值的工具。使用智能手机 CMOS alt 探测器需要针对大多数设备中的外宽价算法采取一些预防措施。测量参考条的荧光（除测试条外）允许校正此类偏差。

Research

JoVE Journal

Environment

Single-plant, Sterile Microcosms for Nodulation and Growth of the Legume Plant Medicago truncatula with the Rhizobial Symbiont Sinorhizobium meliloti

Single-plant, Sterile Microcosms for Nodulation and Growth of the Legume Plant Medicago truncatula with the Rhizobial Symbiont Sinorhizobium meliloti

单厂，无菌的缩影和结瘤的豆科植物生长<em&gt;苜蓿</em&gt;与根瘤菌共生体<em&gt;根瘤菌</em

Rhizobial  bacteria form symbiotic, nitrogen-fixing nodules on the roots of compatible host  legume plants.  One  of the most well-developed model systems ...

科研

环境科学

Tracking Microbial Contamination in Retail Environments Using Fluorescent Powder - A Retail Delicatessen Environment Example

跟踪微生物污染在零售环境中使用荧光粉 - 零售熟食店环境范例

Cross contamination of foodborne pathogens in the retail environment is a significant public health issue contributing to an increased risk for foodborne ...

Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water

Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water

比色纸为基础的检测<em&gt;大肠杆菌</em&gt;<em&gt;沙门氏菌</em&gt;属，和<em&gt;单核细胞增生李斯特氏菌</em&gt;从农业用水大容量

This protocol describes rapid colorimetric detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from large volumes (10 L) of ...

Detection of Foodborne Bacterial Pathogens from Individual Filth Flies

从个人污秽苍蝇检测食源性细菌病原体

There is unanimous consensus that insects are important vectors of foodborne pathogens. However, linking insects as vectors of the pathogen causing a ...

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

生物毒理学方法与海洋细菌<em&gt;鳗弧菌</em&gt;评估环境污染物的急性毒性

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food ...

Building Double-decker Traps for Early Detection of Emerald Ash Borer

建筑双层疏水阀早期检测翡翠灰螟

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), the most destructive forest insect to have invaded North America, has killed hundreds of millions ...

Procedures of Laboratory Fumigation for Pest Control with Nitric Oxide Gas

一氧化氮气体防治害虫实验室熏蒸程序

Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on ...

Characterization of Aquatic Biofilms with Flow Cytometry

流式细胞仪对水生生物膜的表征

Biofilms are dynamic consortia of microorganism that play a key role in freshwater ecosystems. By changing their community structure, biofilms respond ...

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

植物感染试验: 以植物病原菌为载体的喷雾和伤口介导接种

Plants possess a powerful system to defend themselves against potential threats by pathogenic fungi. For agriculturally important plants, however, current ...