來自中科院上海應(yīng)用物理所,，浙江大學(xué)物理學(xué)系,，上海交通大學(xué)生命科學(xué)與技術(shù)學(xué)院的研究人員運(yùn)用分子動(dòng)力學(xué)模擬方法，利用仿生的思想,，參考生物水通道中分布在重要氨基酸殘基上的電荷分布,，利用特定半徑的納米碳管，設(shè)計(jì)出使管內(nèi)水分子定向運(yùn)動(dòng)的納米尺度水泵,，并闡明了相關(guān)的物理機(jī)理,。研究結(jié)果發(fā)表在國(guó)際權(quán)威科學(xué)期刊Nature子期刊——《自然—納米技術(shù)》（Nature Nanotechnology）10月21日的提前網(wǎng)上版上，《自然—納米技術(shù)》同時(shí)刊發(fā)專題評(píng)論文章指出：“……他們的計(jì)算結(jié)果預(yù)言了有一種最佳的電荷排列方式會(huì)使得水被泵向所需的方向,，……該研究成果對(duì)于設(shè)計(jì)用于污水處理,、海水凈化以及生物芯片上的高效納米水泵具有一定的啟示性。”
文章的通訊作者是中科院上海應(yīng)用物理所的方海平研究員,，以及上海交通大學(xué)的生物醫(yī)學(xué)工程專家胡鈞,，后者為上海交大的長(zhǎng)江學(xué)者，特聘教授,。
分子機(jī)器是人類的一個(gè)夢(mèng)想,，是納米科學(xué)技術(shù)的一個(gè)終極目標(biāo)。雖然,，初步的實(shí)驗(yàn)已經(jīng)構(gòu)建了一些簡(jiǎn)單的人工分子器件,，如小的有機(jī)分子棘輪、納米車輪等,，但是由于目前技術(shù)水平的限制，很難做出像生物分子機(jī)器那樣精細(xì)復(fù)雜的結(jié)構(gòu)并實(shí)現(xiàn)其高級(jí)功能,。近年來,，借鑒生物系統(tǒng)中已有的一些本質(zhì)的東西來設(shè)計(jì)具有類似特性的人工分子機(jī)器的思路逐漸獲得人們的重視。這個(gè)納米水泵的設(shè)計(jì)正是這個(gè)思路的一個(gè)體現(xiàn),。
這一工作的一個(gè)核心是限制于這種納米水通道中的水表現(xiàn)出沿著納米水通道軸向的準(zhǔn)一維水鏈,，并在通道內(nèi)形成準(zhǔn)一維氫鍵網(wǎng)絡(luò)的特性。在他們的前期工作中已經(jīng)揭示出,，這樣的準(zhǔn)一維水鏈表現(xiàn)出優(yōu)異的力學(xué)和電學(xué)開關(guān)特性（JACS. 127, 7166-7170,；Proc. Natl. Acad. Sci. USA. 104,3687-3692）,。在參考生物水通道中的電荷分布引起的非對(duì)稱電場(chǎng)作用下，這樣的準(zhǔn)一維水鏈在保持特定的氫鍵方向的同時(shí),，又維持相對(duì)低的通透阻尼,，使水分子定向地從納米管道的一端流向另一端。
原始出處:
Nature Nanotechnology 2, 709 - 712 (2007)
Published online: 21 October 2007 | doi:10.1038/nnano.2007.320
Subject Categories: Nanofluidics | Computational nanotechnology
A charge-driven Lu1,2,4, Rongzheng Wan1, Jichen Li5, Jun Hu1,6 & Haiping Fang1
Abstract
Understanding and controlling the transport of water across nanochannels is of great importance for designing novel molecular devices, machines and sensors and has wide applications1, 2, 3, 4, 5, 6, 7, 8, 9, including the desalination of seawater5. Nanopumps driven by electric or magnetic fields can transport ions10, 11 and magnetic quanta12, but water is charge-neutral and has no magnetic moment. On the basis of molecular dynamics simulations, we propose a design for a molecular water pump. The design uses a combination of charges positioned adjacent to a nanopore and is inspired by the structure of channels in the cellular membrane that conduct water in and out of the cell (aquaporins). The remarkable pumping ability is attributed to the charge dipole-induced ordering of water confined in the nanochannels13, 14, where water can be easily driven by external fields in a concerted fashion. These findings may provide possibilities for developing water transport devices that function without osmotic pressure or a hydrostatic pressure gradient.
Shanghai Institute of Applied Physics, Chinese Academy of Sciences, PO Box 800-204, Shanghai 201800, China
Graduate School of the Chinese Academy of Sciences, Beijing 100080, China
Department of Physics, Zhejiang University, Hangzhou, 310027, China
Department of Physics, Zhejiang Normal University, 321004, Jinhua, China
Department of Physics and Astronomy, The University of Manchester, Manchester M60 1QD, UK
Bio-X Life Sciences Research Center, College of Life Science and Technology, Shanghai JiaoTong University, Shanghai 200030, China
Correspondence to: Jun Hu1,6 e-mail: [email protected]
Correspondence to: Haiping Fang1 e-mail: [email protected]
