Mazumdar Debapriya, Lan Tian, Lu Yi
ANDalyze Inc., 2109 S Oak Street, Champaign, IL, 61820, USA.
Glucosentient Inc., 60 Hazelwood Drive, Champaign, IL, 61820, USA.
Methods Mol Biol. 2017;1571:389-406. doi: 10.1007/978-1-4939-6848-0_24.
Real-time, on-site detection and quantification of different trace analytes is a challenge that requires both searching a general class of molecules to recognize a broad range of contaminants and translating this recognition to easily detectable signals. Functional nucleic acids, which include DNAzymes (DNA with catalytic activity) and aptamers (nucleic acids that bind an analyte), are ideal candidates for the target recognition. These nucleic acids can be selected by a combinatorial biology method called in vitro selection to interact with a particular analyte with high specificity and sensitivity. Furthermore, they can be incorporated into sensors by attaching signaling molecules. Due to the high extinction coefficients and distance-dependent optical properties, metallic nanoparticles such as the commonly used gold nanoparticles have been shown to be very attractive in converting analyte-specific functional DNA into colorimetric sensors. DNAzyme directed assembly of gold nanoparticles has been used to make colorimetric sensors for metal ions such as lead, uranium, and copper. To make the operation even easier and less vulnerable to operator's errors, dipstick tests have been constructed. Here, we describe protocols for the preparation of DNAzyme-linked gold nanoparticles (AuNP) that are then immobilized on to lateral flow devices to make easy-to-use dipstick tests for metal ions.
对不同痕量分析物进行实时、现场检测和定量分析是一项挑战，这既需要寻找一类通用分子以识别广泛的污染物，又需要将这种识别转化为易于检测的信号。功能性核酸，包括脱氧核酶（具有催化活性的DNA）和适体（与分析物结合的核酸），是目标识别的理想候选物。这些核酸可以通过一种称为体外筛选的组合生物学方法进行选择，以与特定分析物以高特异性和灵敏度相互作用。此外，它们可以通过连接信号分子整合到传感器中。由于高消光系数和距离依赖性光学特性，诸如常用的金纳米颗粒等金属纳米颗粒已被证明在将分析物特异性功能性DNA转化为比色传感器方面非常有吸引力。脱氧核酶指导的金纳米颗粒组装已用于制造用于铅、铀和铜等金属离子的比色传感器。为了使操作更加简便且不易受操作人员误差影响，已构建了试纸条检测方法。在此，我们描述了制备与脱氧核酶连接的金纳米颗粒（AuNP）的方案，然后将其固定在侧向流动装置上，以制造用于金属离子的易于使用的试纸条检测方法。
