Teniou Ahlem, Rhouati Amina, Catanante Gaëlle
Bioengineering Laboratory, Higher National School of Biotechnology, Constantine, Algeria.
BAE Laboratory, Perpignan University, Perpignan, France.
Appl Biochem Biotechnol. 2022 May;194(5):1925-1937. doi: 10.1007/s12010-022-03802-1. Epub 2022 Jan 8.
Dopamine (DA) is a catecholamine neurotransmitter playing an important role in different biological functions including central nervous, renal, cardiovascular, and hormonal systems. The sensitive and selective detection of this neurotransmitter plays a key role in the early diagnosis of various diseases related to abnormal levels of dopamine. Therefore, it is of great importance to explore rapid, simple, and accurate methods for detection of dopamine with high sensitivity and specificity. We propose in this work a fluorescent aptasensor based on graphene oxide (GO) as a quencher, for the rapid determination of dopamine. The principle of this aptasensor is based on fluorescence resonance energy transfer (FRET), where GO was used as energy donor, and a carboxy fluorescein (FAM)-labeled aptamer as acceptor. In the absence of DA, FAM-aptamer was adsorbed on the surface of GO through π-π stacking interactions between nucleotide bases and the carbon network, leading to a weak FRET and a quenching of the FAM fluorescence. However, by adding the target, the aptamer undergoes a conformational change to bind to DA with high affinity, resulting in a fluorescence recovery. Under the optimal experimental conditions, the fluorescence recovery was linearly proportional to the concentration of DA in the range of 3-1680 nM, with a limit of detection of 0.031 nM and a limit of quantification of 0.1 nM. Moreover, the developed assay exhibited minor response in the presence of various interferents and it revealed a satisfactory applicability in human serum samples.
多巴胺（DA）是一种儿茶酚胺神经递质，在包括中枢神经、肾脏、心血管和激素系统在内的不同生物学功能中发挥着重要作用。对这种神经递质进行灵敏且选择性的检测，在与多巴胺水平异常相关的各种疾病的早期诊断中起着关键作用。因此，探索快速、简便且准确的高灵敏度和特异性检测多巴胺的方法具有重要意义。在这项工作中，我们提出了一种基于氧化石墨烯（GO）作为猝灭剂的荧光适体传感器，用于快速测定多巴胺。该适体传感器的原理基于荧光共振能量转移（FRET），其中GO用作能量供体，羧基荧光素（FAM）标记的适体用作受体。在没有多巴胺的情况下，FAM标记的适体通过核苷酸碱基与碳网络之间的π-π堆积相互作用吸附在GO表面，导致FRET减弱和FAM荧光猝灭。然而，通过添加目标物，适体会发生构象变化，以高亲和力与多巴胺结合，从而导致荧光恢复。在最佳实验条件下，荧光恢复与3-1680 nM范围内的多巴胺浓度呈线性比例关系，检测限为0.031 nM，定量限为0.1 nM。此外，所开发的检测方法在存在各种干扰物时表现出较小的响应，并且在人血清样本中显示出令人满意的适用性。
