We designed a universal and sensitive fluorometric aptasensor that uses a fluorescence resonance energy transfer (FRET) mechanism. In the aptasensor, water-soluble conjugated poly(9,9-bis(6′-N,N,N-trimethylammonium)hexyl)fluorine phenylene (PFP) is used as the energy donor and a carboxyfluorescein (FAM)-labeled aptamer is used as the energy acceptor. Graphene oxide (GO) used as a quencher can specifically adsorb the aptamer, leading to quenching of the FAM fluorescence. In the presence of targets, the aptamer can change its conformation to prevent adsorption by GO. Strong FRET was thus obtained owing to the electrostatic interactions between PFP and the aptamer. In contrast, in the absence of targets, the FRET was weak because of GO specifically adsorbing the aptamer and quenching the fluorescence. Bisphenol A (a pollutant molecule) and dopamine (a biomolecule) were used as models to successfully validate the feasibility, universality, and high selectivity and sensitivity of this aptasensor. This method can detect BPA at environmentally relevant concentrations (less than 1 ng/mL) with a limit of detection of 0.005 ng/mL. A low limit of detection (1.0 nmol/L) was also obtained for dopamine. In addition, this aptasensor is applicable in real samples and in diluted human plasma and human serum. Good recovery rates from 95% to 105% and from 95% to 107% were obtained for bisphenol A and dopamine, respectively. Furthermore, adenosine detection was successfully achieved by the same mechanism, proving the universality. It is expected that the aptasensor could be applied in detecting other contaminants, biomolecules, and heavy metal ions by a change in only the aptamer sequence.

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基于水溶性共轭聚合物/氧化石墨烯的通用荧光适体传感器平台

我们设计了一种通用且灵敏的荧光适体传感器，它使用了荧光共振能量转移（FRET）机制。在适体传感器中，水溶性共轭聚（9,9-bis（6'- N，N，N-三甲基铵）己基）氟亚苯基（PFP）被用作能量供体，羧基荧光素（FAM）标记的适体被用作能量受体。用作淬灭剂的氧化石墨烯（GO）可以特异性地吸附适体，从而导致FAM荧光淬灭。在存在靶标的情况下，适体可以改变其构象以防止GO吸附。由于PFP和适体之间的静电相互作用，因此获得了强FRET。相反，在没有靶标的情况下，由于GO特异性吸附适体并猝灭荧光，因此FRET较弱。使用双酚A（一种污染物分子）和多巴胺（一种生物分子）作为模型来成功验证该适体传感器的可行性，通用性，高选择性和灵敏度。该方法可以检测与环境相关的浓度（小于1 ng / mL）中的BPA，检测限为0.005 ng / mL。多巴胺的检测限也很低（1.0 nmol / L）。另外，该适体传感器适用于真实样品以及稀释的人血浆和人血清。双酚A和多巴胺的回收率分别为95％至105％和95％至107％。此外，通过相同的机制成功实现了腺苷检测，证明了其普遍性。期望适体传感器可通过仅改变适体序列而应用于检测其他污染物，生物分子和重金属离子。该适体传感器适用于真实样品以及稀释的人血浆和人血清。双酚A和多巴胺的回收率分别为95％至105％和95％至107％。此外，通过相同的机制成功实现了腺苷检测，证明了其普遍性。期望适体传感器可通过仅改变适体序列而应用于检测其他污染物，生物分子和重金属离子。该适体传感器适用于真实样品以及稀释的人血浆和人血清。双酚A和多巴胺的回收率分别为95％至105％和95％至107％。此外，通过相同的机制成功实现了腺苷检测，证明了其普遍性。期望适体传感器可通过仅改变适体序列而应用于检测其他污染物，生物分子和重金属离子。