Gold Nanoparticles Adsorb DNA and Aptamer Probes Too Strongly and a Comparison with Graphene Oxide for Biosensing
Gold Nanoparticles Adsorb DNA and Aptamer Probes Too Strongly and a Comparison with Graphene Oxide for Biosensing
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金纳米粒子对 DNA 和适体探针的吸附力过强以及与氧化石墨烯生物传感的比较
DOI：
10.1021/acs.analchem.9b04142
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发表时间：
2019
影响因子：
7.4
通讯作者：
Liu Juewen
中科院分区：
文献类型：
--
作者：
Zhang Fang;Wang Shaoyun;Liu Juewen
利用荧光标记的DNA寡核苷酸和纳米材料开发生物传感器已被广泛报道为金纳米颗粒（AuNPs）和氧化石墨烯（GO）等。这些材料具有截然不同的亲和力和与DNA相互作用的机制，它们的分析性能可能不同。在这项工作中，我们使用了几个DNA序列，并分别将它们吸附在aunp和GO上以猝灭荧光。与以往工作不同的是，我们使用KCN完全溶解AuNPs来计算由于互补DNA （cDNA）和适体靶点而解吸的DNA的百分比。从AuNPs中脱附的探针DNA对包括DNA、腺苷、Hg2+和溶菌酶在内的所有靶标的吸附率都小于5%，表明其具有很强的DNA吸附亲和力。通过添加HEPES缓冲液、NaCl和As（III）来实现DNA的脱附，但这种脱附是由于这些分子或离子被AuNPs吸附而不是与被吸附的DNA相互作用。对于氧化石墨烯，随着目标分析物的加入，更多的探针解吸，但随机DNA和蛋白质的非特异性解吸也是如此。综上所述，对于仅依靠探针DNA的解吸来开发生物传感器来说，aunp不太可能是一个好的表面，而对于氧化石墨烯来说，主要问题是非特异性解吸。
Using fluorescently labeled DNA oligonucleotides and nanomaterials for developing biosensors has been extensively reported for gold nanoparticles (AuNPs) and graphene oxide (GO) among others. These materials have vastly different affinities and mechanisms for interacting with DNA, and their analytical performance is likely to be different. In this work, we used several DNA sequences and, respectively, adsorbed them on AuNPs and GO to quench fluorescence. Different from previous work, we used KCN to fully dissolve the AuNPs to calculate the percentage of the desorbed DNA due to the complementary DNA (cDNA) and aptamer target. The desorbed probe DNA from the AuNPs was less than 5% for all of the targets including DNA, adenosine, Hg2+, and lysozyme, indicating a very strong DNA adsorption affinity. Desorption of DNA was achieved by adding HEPES buffer, NaCl, and As(III), but such desorption was attributed to the adsorption of these molecules or ions by the AuNPs instead of their interaction with the adsorbed DNA. For GO, more probes desorbed with addition of target analytes but so did nonspecific desorption by random DNA and proteins. In summary, AuNPs are unlikely to be a good surface for developing biosensors relying solely on the desorption of probe DNA, while for GO the main problem is nonspecific desorption.