Environmental Toxicology and ‡Department of Chemistry, University of California-Riverside , Riverside, California 92521, United States.
Anal Chem. 2017 Apr 4;89(7):4272-4279. doi: 10.1021/acs.analchem.7b00341. Epub 2017 Mar 24.
A novel bioconjugation strategy leading to ultrastable gold nanoparticles (AuNPs), utilizing DNA linkers and diluents in place of traditional self-assembled monolayers, is reported. The protective capacity of DNA confers straightforward biomolecular attachment and multistep derivatization capabilities to these nanoparticles and, more significantly, substantially enhances their stability in demanding and complex sensing environments. The DNA/AuNPs were assembled through pH-assisted thiol-gold bonding of single stranded DNA and salt aging, with preconjugated biotin moieties facing outward from the gold surface. These nanoparticles remain a stable colloidal suspension under a wide range of buffers and ionic strengths and can endure multiple rounds of lyophilization while retaining high biological activity. Furthermore, the high stability of the DNA/AuNPs allows for multiple reactions and conjugations to be performed within the colloidal suspensions (i.e., Protein A and antibody binding) for tailored and specific recognition to take place. We have demonstrated the applications of the DNA/AuNPs for colorimetric assays and ELISA feasibility; additionally, SPR imaging analysis of a supported membrane microarray shows excellent results with DNA/AuNPs as the enhancing agent. Together, the properties imparted by this interface render the material suitable for clinical and point-of-care applications where stability, throughput, and extended shelf lives are needed.
一种新的生物偶联策略导致超稳定的金纳米粒子（AuNPs），利用 DNA 接头和稀释剂代替传统的自组装单分子层。DNA 的保护能力赋予这些纳米粒子直接的生物分子附着和多步衍生化能力，更重要的是，大大提高了它们在苛刻和复杂的传感环境中的稳定性。DNA/AuNPs 通过 pH 辅助的单链 DNA 的巯基-金键合和盐老化组装而成，预共轭的生物素部分从金表面向外突出。这些纳米粒子在广泛的缓冲液和离子强度下仍保持稳定的胶体悬浮液，并能耐受多次冻干，同时保持高生物活性。此外，DNA/AuNPs 的高稳定性允许在胶体悬浮液中进行多次反应和偶联（即，蛋白 A 和抗体结合），以实现定制和特定的识别。我们已经证明了 DNA/AuNPs 在比色分析和 ELISA 中的应用可行性；此外，支撑膜微阵列的 SPR 成像分析显示，DNA/AuNPs 作为增强剂具有优异的结果。总的来说，这种界面赋予的特性使该材料适合于需要稳定性、高通量和延长保质期的临床和即时护理应用。
