Size effects on diffusion processes within agarose gels

被引:190
作者
Fatin-Rouge, N [1 ]
Starchev, K [1 ]
Buffle, J [1 ]
机构
[1] Univ Geneva, Geneva, Switzerland
关键词
D O I
10.1016/S0006-3495(04)74325-8
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
To investigate diffusion processes in agarose gel, nanoparticles with sizes in the range between 1 and 140 nm have been tested by means of fluorescence correlation spectroscopy. Understanding the diffusion properties in agarose gels is interesting, because such gels are good models for microbial biofilms and cells cytoplasm. The fluorescence correlation spectroscopy technique is very useful for such investigations due to its high sensitivity and selectivity, its excellent spatial resolution compared to the pore size of the gel, and its ability to probe a wide range of sizes of diffusing nanoparticles. The largest hydrodynamic radius (R-c) of trapped particles that displayed local mobility was estimated to be 70 nm for a 1.5% agarose gel. The results showed that diffusion of particles in agarose gel is anomalous, with a diverging fractal dimension of diffusion when the large particles become entrapped in the pores of the gel. The latter situation occurs when the reduced size (R-A/R-c) of the diffusing particle, A, is >0.4. Variations of the fractal exponent of diffusion (d(w)) with the reduced particle size were in agreement with three-dimensional Monte Carlo simulations in porous media. Nonetheless, a systematic offset of d(w) was observed in real systems and was attributed to weak nonelastic interactions between the diffusing particles and polymer fibers, which was not considered in the Monte Carlo simulations.
引用
收藏
页码:2710 / 2719
页数:10
相关论文
共 49 条
[1]  
ABRAGAM A, 1964, MAGNETIZATION NUCL, P67
[2]   Solute diffusion in hydrogels. An examination of the retardation effect [J].
Amsden, B .
POLYMER GELS AND NETWORKS, 1998, 6 (01) :13-43
[3]   FLUORESCENCE CORRELATION SPECTROSCOPY AS A PROBE OF MOLECULAR-DYNAMICS [J].
ARAGON, SR ;
PECORA, R .
JOURNAL OF CHEMICAL PHYSICS, 1976, 64 (04) :1791-1803
[4]   2-PHOTON FLUORESCENCE CORRELATION SPECTROSCOPY - METHOD AND APPLICATION TO THE INTRACELLULAR ENVIRONMENT [J].
BERLAND, KM ;
SO, PTC ;
GRATTON, E .
BIOPHYSICAL JOURNAL, 1995, 68 (02) :694-701
[5]   ANOMALOUS DIFFUSION IN DISORDERED MEDIA - STATISTICAL MECHANISMS, MODELS AND PHYSICAL APPLICATIONS [J].
BOUCHAUD, JP ;
GEORGES, A .
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 1990, 195 (4-5) :127-293
[6]  
Buffle J., 1988, Complexation Reactions in Aquatic Systems
[7]  
BUNDE A, 1991, FRACTAL DISORDERED S
[8]  
DeRossi D., 1991, Polymer Gels
[9]   Diffusion and partitioning of solutes in agarose hydrogels: The relative influence of electrostatic and specific interactions [J].
Fatin-Rouge, N ;
Milon, A ;
Buffle, J ;
Goulet, RR ;
Tessier, A .
JOURNAL OF PHYSICAL CHEMISTRY B, 2003, 107 (44) :12126-12137
[10]  
GHOSH RN, 1988, BIOPHYS J, V53, pA352