School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu212013, P.R. China.
College of Food and Biological Engineering, Jimei University, Xiamen, Fujian361021, P.R. China.
J Agric Food Chem. 2023 Jan 11;71(1):857-866. doi: 10.1021/acs.jafc.2c06850. Epub 2022 Dec 23.
Reproducibility and stability are important indicators for the evaluation of quantitative sensing methods based on surface-enhanced Raman scattering (SERS) technology. Developing a SERS substrate with self-calibration capabilities is vital for effectively quantifying targets. In this work, a competitive ratiometric SERS aptasensor was developed. 4-Aminothiophenol as an internal standard (IS) was embedded in the substrate followed by gradually loading with the aptamer and methylene blue functionalizing of the complementary sequences of the aptamer (MB-cDNA). Recognition and binding of the target to the aptamer resulted in the shedding of MB-cDNA after magnetic separation reducing the SERS signal of MB, allowing for the ratiometric determination of the target based on the constant intensity from the IS. For the selective detection of okadaic acid (OA), a good negative correlation was achieved between the SERS ratiometric intensity and OA concentration in the range of 0.5-100 ng/mL. The magnetic separation strategy effectively simplifies the production steps of the aptasensor, and the ratiometric strategy effectively improved the reproducibility and stability of the OA sensing. This ratiometric aptasensor has been successfully employed to detect OA in food and environmental samples and is expected to be extended to detect other targets.
重现性和稳定性是基于表面增强拉曼散射（SERS）技术的定量传感方法评价的重要指标。开发具有自校准能力的 SERS 基底对于有效地定量目标至关重要。在这项工作中，开发了一种竞争性比率型 SERS 适体传感器。将 4-巯基苯胺作为内标（IS）嵌入基底中，然后逐渐加载适体和甲基蓝修饰的适体互补序列（MB-cDNA）。目标与适体的识别和结合导致磁分离后 MB-cDNA 的脱落，从而降低了 MB 的 SERS 信号，允许基于 IS 的恒定强度进行目标的比率测定。为了选择性检测 okadaic 酸（OA），在 0.5-100ng/mL 的范围内，SERS 比率强度与 OA 浓度之间呈现出良好的负相关性。磁分离策略有效地简化了适体传感器的生产步骤，而比率策略则有效地提高了 OA 传感的重现性和稳定性。该比率型适体传感器已成功用于检测食品和环境样品中的 OA，并有望扩展到检测其他目标。
