Cattaruzza Fabrizio, Cricenti Antonio, Flamini Alberto, Girasole Marco, Longo Giovanni, Prosperi Tommaso, Andreano Giuseppina, Cellai Luciano, Chirivino Emanuele
Istituto di Struttura della Materia, CNR, Via Salaria Km 29,300, 00016 Monterotondo Stazione, Rome, Italy.
Nucleic Acids Res. 2006 Feb 28;34(4):e32. doi: 10.1093/nar/gnj034.
Unoxidized crystalline silicon, characterized by high purity, high homogeneity, sturdiness and an atomically flat surface, offers many advantages for the construction of electronic miniaturized biosensor arrays upon attachment of biomolecules (DNA, proteins or small organic compounds). This allows to study the incidence of molecular interactions through the simultaneous analysis, within a single experiment, of a number of samples containing small quantities of potential targets, in the presence of thousands of variables. A simple, accurate and robust methodology was established and is here presented, for the assembling of DNA sensors on the unoxidized, crystalline Si(100) surface, by loading controlled amounts of a monolayer DNA-probe through a two-step procedure. At first a monolayer of a spacer molecule, such as 10-undecynoic acid, was deposited, under optimized conditions, via controlled cathodic electrografting, then a synthetic DNA-probe was anchored to it, through amidation in aqueous solution. The surface coverage of several DNA-probes and the control of their efficiency in recognizing a complementary target-DNA upon hybridization were evaluated by fluorescence measurements. The whole process was also monitored in parallel by Atomic Force Microscopy (AFM).
未氧化的晶体硅具有高纯度、高均匀性、坚固性以及原子级平整的表面，在附着生物分子（DNA、蛋白质或小有机化合物）后，为构建电子微型化生物传感器阵列提供了诸多优势。这使得能够在单个实验中，通过对包含少量潜在靶标的多个样品进行同步分析，在数千个变量存在的情况下，研究分子相互作用的发生率。本文建立并展示了一种简单、准确且稳健的方法，用于在未氧化的晶体Si(100)表面组装DNA传感器，该方法通过两步程序加载可控量的单层DNA探针。首先，在优化条件下，通过可控阴极电接枝沉积一层间隔分子，如10 - 十一碳烯酸，然后通过在水溶液中酰胺化将合成的DNA探针锚定到其上。通过荧光测量评估了几种DNA探针的表面覆盖率及其在杂交时识别互补靶标DNA的效率。整个过程还通过原子力显微镜（AFM）进行了并行监测。
