Zhu Lin, Zeng Wei, Li Yueqing, Han Yu, Wei Jing, Wu Long
Hubei Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, College of Life Sciences and Technology, Hubei Engineering University, Xiaogan, 432000, Hubei, PR China.
Hainan Engineering Research Center of Aquatic Resources Efficient Utilization in South China Sea, Key Laboratory of Seafood Processing of Haikou, School of Food Science and Technology, Hainan University, Hainan 570228, PR China.
Sci Total Environ. 2024 Apr 15;921:171236. doi: 10.1016/j.scitotenv.2024.171236. Epub 2024 Feb 25.
In this work, on the basis of FeO@Au-Pt nanozymes (MAP NZs) and aptamer recognition, a magnetic fluorescent aptasensor (MFA) was developed for sensitive and accurate detection of saxitoxin (STX). With the bridge of STX aptamer (Apt) and complementary DNA (cDNA), Apt decorated MAP NZs (MAP/Apt) and cDNA modified green quantum dots (cDNA@g-QDs) were connected to form MAP/Apt-cDNA@g-QDs complex. As STX behaves a strong binding ability towards Apt, it will compete with cDNA and hybridize with Apt to release cDNA@g-QDs. With the addition of TMB, MAP will catalyze TMB to the oxidized TMB (ox-TMB), thereby quenching the fluorescence of g-QDs due to the inner filter effect. Based on this finding, the quantitative relationship between the change in fluorescence of gQDs and STX concentration was explored with a limit of detection (LOD, S/N = 3) of 0.6 nM. An internal standard signal of oxTMB was adopted and reduced the fluctuation of fluorescence signal output. Besides, the fluorescence probe can selectively recognize and detect STX among five marine toxins. Eventually, the MFA method behaved good performance in detecting seafood samples with recoveries of 82.0 % ∼ 102.6 % as well as coefficient of variations (CV) of 7.2 % ∼ 10.3 %. Therefore, the method with internal signal is hopeful to be a potential candidate for sensitive and accurate detection of STX in seafood.
在这项工作中，基于FeO@Au-Pt纳米酶（MAP纳米酶）和适配体识别，开发了一种用于灵敏、准确检测麻痹性贝类毒素（STX）的磁性荧光适配体传感器（MFA）。以STX适配体（Apt）和互补DNA（cDNA）为桥梁，将Apt修饰的MAP纳米酶（MAP/Apt）和cDNA修饰的绿色量子点（cDNA@g-QDs）连接起来，形成MAP/Apt-cDNA@g-QDs复合物。由于STX对Apt具有很强的结合能力，它会与cDNA竞争并与Apt杂交，从而释放出cDNA@g-QDs。加入3,3',5,5'-四甲基联苯胺（TMB）后，MAP会将TMB催化氧化为氧化型TMB（ox-TMB），进而由于内滤效应淬灭g-QDs的荧光。基于这一发现，研究了g-QDs荧光变化与STX浓度之间的定量关系，检测限（LOD，S/N = 3）为0.6 nM。采用ox-TMB的内标信号，降低了荧光信号输出的波动。此外，该荧光探针能够在五种海洋毒素中选择性地识别和检测STX。最终，MFA方法在检测海鲜样品时表现出良好的性能，回收率为82.0% ∼ 102.6%，变异系数（CV）为7.2% ∼ 10.3%。因此，这种具有内部信号的方法有望成为灵敏、准确检测海鲜中STX的潜在候选方法。
