Competing ligand assisted aptamers and DNAzymes for nanomaterials

脱氧核糖核酸(DNA)序列可与无机纳米材料结合，具有高亲和力和高特异性，可用于生物传感器的开发、生物矿化和材料的定向组装。然而，强烈的非特异性相互作用使得获得高质量的表面DNA适配子变得困难。此外，我们对探索用于支持催化的表面很感兴趣。目前建议的目标是选择能够选择性结合到无机表面的DNA序列(适配子)和基于DNA的酶(DNAzyme)，使用无机纳米颗粒作为辅助催化因子。与以往的研究不同，我们将使用离子和竞争分子来调节相互作用的强度，从而将非特异性DNA的吸附减弱到与DNA之间的碱基配对相互作用相当的程度。在这样的条件下，我们可以获得能够特异性识别表面特征的DNA序列。我们将选择包括氧化铁、氧化石墨烯和金在内的几个无机表面来使用大型随机DNA文库进行适体选择。此外，DNAzyme的选择将在无机纳米材料存在的情况下进行，目的是将表面用作辅助因子。选定的DNA适配子和DNA酶将在结合强度和催化效率方面进行仔细的表征。将使用各种光谱技术研究它们与目标表面的相互作用，并探索它们在分析和材料方面的应用。这项研究将拓宽我们对DNA/纳米界面的理解，产生用于表面功能化和识别的特定DNA序列，并产生有趣的生物传感器和杂化材料。

Deoxyribonucleic acid (DNA) sequences that can bind to inorganic nanomaterials with high affinity and specificity are useful for biosensor development, biomineralization, and directed assembly of materials. However, strong nonspecific interactions make it difficult to obtain high quality DNA aptamers for surfaces. In addition, we are interested in exploring surfaces for supporting catalysis. The goal of the current proposal is to select DNA sequences (aptamers) that can selectively bind to inorganic surfaces and DNA-based enzymes (DNAzymes) using inorganic nanoparticles as cofactors for catalysis. Different from previous research, we will use ions and competing molecules to modulate the interaction strength so that nonspecific DNA adsorption is weakened to a degree comparable with the base pairing interactions between DNA. Under such conditions, we may obtain DNA sequences that can specifically recognize surface features. We will choose a few inorganic surfaces including iron oxide, graphene oxide and gold to perform aptamer selections using a large random DNA library. In addition, selection of DNAzymes will be performed in the presence of inorganic nanomaterials with the goal to use the surfaces as cofactors. The selected DNA aptamers and DNAzymes will be carefully characterized in terms of binding strength and catalytic efficiency. Their interactions with the target surfaces will be studied using various spectroscopic techniques, and their analytical and materials applications will be explored. This study will broaden our understanding of DNA/nano interfaces, generate specific DNA sequences for surface functionalization and recognition, and produce interesting biosensors and hybrid materials.