The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate str...The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate strategies for designing anti-fouling surfaces are crucial.Here,we employ molecular dynamics simulations and alchemical free energy calculations to systematically analyze the factors influencing resistance to protein adsorption on the SAMs terminated with single or double OH groups at three packing densities(∑=2.0 nm^(-2),4.5 nm^(-2),and 6.5 nm^(-2)),respectively.For the first time,we observed that the compactness and order of interfacial water enhance its physical barrier effect,subsequently enhancing the resistance of SAM to protein adsorption.Notably,the spatial hindrance effect of SAM leads to the embedding of protein into SAM,resulting in a lack of resistance of SAM towards protein.Furthermore,the number of hydroxyl groups per unit area of double OH-terminated SAM at ∑=6.5 nm^(-2) is approximately 2 to 3 times that of single OH-terminated SAM at ∑=6.5 nm^(-2) and 4.5 nm^(-2),consequently yielding a weaker resistance of double OH-terminated SAM towards protein.Meanwhile,due to the structure of SAM itself,i.e.,the formation of a nearly perfect ice-like hydrogen bond structure,the SAM exhibits the weakest resistance towards protein.This study will complement and improve the mechanism of OH-SAM resistance to protein adsorption,especially the traditional barrier effect of interfacial water.展开更多
Flipping of water dipoles in carbon nanotubes is of great importance in many physical and biological applications,such as signal amplification,molecular switches and nano-gates.Ahead of these applications,understandin...Flipping of water dipoles in carbon nanotubes is of great importance in many physical and biological applications,such as signal amplification,molecular switches and nano-gates.Ahead of these applications,understanding and inhibiting the non-negligible thermal noise is essential.Here,we use molecular dynamics simulations to show that the flipping frequency of water dipoles increases with the rising temperature,and the thermal noise can be suppressed by imposed charges and external uniform electric fields.Furthermore,the water dipoles flip periodically between two equiprobable and stable states under alternating electric fields.These two stable states may be adopted to store 0 and 1 bits for memory storage or molecular computing.展开更多
基金Project supported by the National Natural Science Foundation of China (Grants No. 12075201)the Science and Technology Planning Project of Jiangsu Province, China (Grant No. BK20201428)+1 种基金the Postgraduate Research & Practice Innovation Program of Jiangsu Province, China (Grant No. KYCX21 3193)the Special Program for Applied Research on Supercomputation of the NSFC–Guangdong Joint Fund (the second phase)。
文摘The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate strategies for designing anti-fouling surfaces are crucial.Here,we employ molecular dynamics simulations and alchemical free energy calculations to systematically analyze the factors influencing resistance to protein adsorption on the SAMs terminated with single or double OH groups at three packing densities(∑=2.0 nm^(-2),4.5 nm^(-2),and 6.5 nm^(-2)),respectively.For the first time,we observed that the compactness and order of interfacial water enhance its physical barrier effect,subsequently enhancing the resistance of SAM to protein adsorption.Notably,the spatial hindrance effect of SAM leads to the embedding of protein into SAM,resulting in a lack of resistance of SAM towards protein.Furthermore,the number of hydroxyl groups per unit area of double OH-terminated SAM at ∑=6.5 nm^(-2) is approximately 2 to 3 times that of single OH-terminated SAM at ∑=6.5 nm^(-2) and 4.5 nm^(-2),consequently yielding a weaker resistance of double OH-terminated SAM towards protein.Meanwhile,due to the structure of SAM itself,i.e.,the formation of a nearly perfect ice-like hydrogen bond structure,the SAM exhibits the weakest resistance towards protein.This study will complement and improve the mechanism of OH-SAM resistance to protein adsorption,especially the traditional barrier effect of interfacial water.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11875236,61575178,11574272 and U1832150the Zhejiang Provincial Natural Science Foundation under Grant Nos LY16A040014 and LY18A040001the Zhejiang Provincial Science and Technology Project under Grant No LGN18C200017
文摘Flipping of water dipoles in carbon nanotubes is of great importance in many physical and biological applications,such as signal amplification,molecular switches and nano-gates.Ahead of these applications,understanding and inhibiting the non-negligible thermal noise is essential.Here,we use molecular dynamics simulations to show that the flipping frequency of water dipoles increases with the rising temperature,and the thermal noise can be suppressed by imposed charges and external uniform electric fields.Furthermore,the water dipoles flip periodically between two equiprobable and stable states under alternating electric fields.These two stable states may be adopted to store 0 and 1 bits for memory storage or molecular computing.
