There is a great need for fast, simple and precise diagnostic assays capable of direct quantification of biomarkers in complex biological matrices. Yet, the commonly used techniques such as ELISA/Immunoassays are tedious and involve various steps e.g. blocking, washing and signal development. Moreover, most of these assays have very limited ability of detecting small molecules and have hardly any multiplexing capabilities. The gold standard and alternative, mass-spectrometry, however, depends upon expensive hardware and is incompatible with point of care (POC) diagnostics. As opposed to POC assays for proteins or larger targets where variable formats are readily available.

Here, we present a simple, versatile and fast one-step assay for detecting a small molecule, ethanolamine as example. The assay makes use of commonly available qPCR machines to detect target-concentration dependent shifts in the melting temperatures of aptamer beacons. The method allows detection of ethanolamine in the low nM range without requiring tedious elaboration of assay conditions as required for molecular beacons at room temperature. If generalizable, it may change the situation of small molecule assays significantly.

迫切需要能够直接定量复杂生物基质中生物标志物的快速，简单和精确的诊断检测方法。然而，诸如ELISA /免疫测定法之类的常用技术是乏味的，并且涉及各种步骤，例如阻断，洗涤和信号产生。而且，这些测定中的大多数具有检测小分子的能力非常有限，并且几乎没有任何多路复用能力。但是，金标准和替代质谱法取决于昂贵的硬件，并且与即时诊断（POC）诊断不兼容。与蛋白质或更大靶标的POC分析相反，在这种情况下，可变格式很容易获得。

在这里，我们提出了一种简单，通用和快速的一步测定法，用于检测小分子乙醇胺为例。该测定法利用常用的qPCR机器来检测适体信标的解链温度与靶标浓度有关的变化。该方法允许检测低nM范围内的乙醇胺，而无需繁琐地阐述室温下分子信标所需的测定条件。如果可以推广，它可能会大大改变小分子测定的情况。