Department of Chemistry, Columbia University , 3000 Broadway, New York, New York 10027 United States.
Department of Electrical Engineering, Columbia University , 500 W. 120th Street, New York, New York 10027 United States.
Nano Lett. 2016 Jul 13;16(7):4679-85. doi: 10.1021/acs.nanolett.6b02149. Epub 2016 Jun 7.
A new approach to synthetic chemistry is performed in ultraminiaturized, nanofabricated reaction chambers. Using lithographically defined nanowells, we achieve single-point covalent chemistry on hundreds of individual carbon nanotube transistors, providing robust statistics and unprecedented spatial resolution in adduct position. Each device acts as a sensor to detect, in real-time and through quantized changes in conductance, single-point functionalization of the nanotube as well as consecutive chemical reactions, molecular interactions, and molecular conformational changes occurring on the resulting single-molecule probe. In particular, we use a set of sequential bioconjugation reactions to tether a single-strand of DNA to the device and record its repeated, reversible folding into a G-quadruplex structure. The stable covalent tether allows us to measure the same molecule in different solutions, revealing the characteristic increased stability of the G-quadruplex structure in the presence of potassium ions (K(+)) versus sodium ions (Na(+)). Nanowell-confined reaction chemistry on carbon nanotube devices offers a versatile method to isolate and monitor individual molecules during successive chemical reactions over an extended period of time.
在超微缩、纳米制造的反应室内进行新的合成化学方法。使用光刻定义的纳米井，我们在数百个单个碳纳米管晶体管上实现单点共价化学，在加合物位置提供稳健的统计学和前所未有的空间分辨率。每个器件都充当传感器，通过电导的量化变化实时检测碳纳米管的单点功能化以及随后的化学反应、分子相互作用和在所得单分子探针上发生的分子构象变化。特别是，我们使用一系列连续的生物缀合反应将单链 DNA 连接到器件上，并记录其重复的、可逆的折叠成 G-四链体结构。稳定的共价键合允许我们在不同的溶液中测量相同的分子，揭示了在存在钾离子 (K(+)) 时 G-四链体结构的特征增加稳定性相对于钠离子 (Na(+))。碳纳米管器件上的纳米井限制反应化学为在延长的时间内隔离和监测单个分子在连续化学反应过程中的情况提供了一种通用方法。
