School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P. R. China.
Anal Chem. 2024 Jun 25;96(25):10391-10398. doi: 10.1021/acs.analchem.4c01554. Epub 2024 Jun 6.
DNA-templated silver nanoclusters (AgNCs-DNA) can be synthesized via a one-pot method bypassing the tedious process of biomolecular labeling. Appending an aptamer to DNA templates results in dual-functionalized DNA strands that can be utilized for synthesizing aptamer-modified AgNCs, thereby enabling the development of label-free fluorescence aptasensors. However, a major challenge lies in the necessity to redesign the dual-functionalized DNA strand for each specific target, thus increasing the complexity and hindering widespread application of these aptasensors. To overcome this challenge, we designed six DNA strands (DNA1-DNA6) that incorporate the templates for AgNCs synthesis and A4-linker for further aptamer coupling. Among all the synthesized AgNCs-DNA samples, it was found that both AgNCs-DNA1 and AgNCs-DNA2 stood out for their excellent long-term stability. After capturing the T4-linker that connected with aptamer1 specific for aflatoxin B1 (AFB1), however, we found that only AgNCs-DNA1/aptamer1 maintained excellent long-term stability. This finding highlighted the potential of AgNCs-DNA1 as a versatile label-free fluorescence probe for the development of on-demand fluorescence aptasensors. To emphasize its benefits in aptasensing applications, we utilized AgNCs-DNA1/aptamer1 as the fluorescence probe and MoS nanosheets as the quencher to develop a FRET aptasensor for AFB1 detection. This aptasensor demonstrated remarkable sensitivity, enabling the detection of AFB1 within a wide concentration range of 0.03-120 ng/mL, with a limit of detection as low as 3.6 pg/mL (/ = 3). The versatility of the aptasensor has been validated through the recognition of diverse targets, employing aptamer2 specific for ochratoxin A and aptamer3 specific for zearalenone, thereby showcasing its extensive applicability for on-demand detection. The universal applicability of this aptasensor holds great promise for future applications in diverse fields including food safety, environmental monitoring, and clinical diagnosis.
DNA 模板银纳米团簇（AgNCs-DNA）可以通过一锅法合成，绕过繁琐的生物分子标记过程。在 DNA 模板上添加适体可得到双功能化的 DNA 链，可用于合成适体修饰的 AgNCs，从而开发无标记荧光适体传感器。然而，主要的挑战在于需要为每个特定目标重新设计双功能化的 DNA 链，从而增加了这些适体传感器的复杂性并阻碍了其广泛应用。为了克服这一挑战，我们设计了 6 条 DNA 链（DNA1-DNA6），其中包含 AgNCs 合成的模板和 A4 接头，用于进一步与适体偶联。在所合成的所有 AgNCs-DNA 样品中，发现 AgNCs-DNA1 和 AgNCs-DNA2 因其出色的长期稳定性而脱颖而出。然而，在捕获与适体 1 特异性结合的 T4 接头（该适体 1 特异性结合黄曲霉毒素 B1（AFB1）后，我们发现只有 AgNCs-DNA1/aptamer1 保持了出色的长期稳定性。这一发现突显了 AgNCs-DNA1 作为一种通用的无标记荧光探针用于按需荧光适体传感器开发的潜力。为了强调其在适体传感应用中的优势，我们将 AgNCs-DNA1/aptamer1 用作荧光探针，将 MoS 纳米片用作猝灭剂，开发了用于检测 AFB1 的 FRET 适体传感器。该适体传感器表现出优异的灵敏度，能够在 0.03-120ng/mL 的宽浓度范围内检测 AFB1，检测限低至 3.6pg/mL（/ = 3）。该适体传感器的通用性已通过对不同目标的识别得到验证，使用了针对赭曲霉毒素 A 的适体 2 和针对玉米赤霉烯酮的适体 3，从而展示了其广泛适用于按需检测的应用。这种适体传感器的通用性为其在食品安全、环境监测和临床诊断等不同领域的未来应用提供了广阔的前景。
