Probing the modifications of polystyrene surface properties after incubation with theShewanella putrefaciens bacteria at two pH values (4, 10) by atomic force microscopy

2007 ◽  
Vol 39 (7) ◽  
pp. 648-652 ◽  
Author(s):  
Fabien Gaboriaud ◽  
Sidney Bailet ◽  
Etienne Dague ◽  
Frédéric Jorand
1999 ◽  
Vol 38 (Part 1, No. 6B) ◽  
pp. 3936-3939 ◽  
Author(s):  
Futoshi Iwata ◽  
Tarou Matsumoto ◽  
Ryuhei Ogawa ◽  
Akira Sasaki

RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 25789-25798 ◽  
Author(s):  
Sumit Arora ◽  
Michael Kappl ◽  
Mehra Haghi ◽  
Paul M. Young ◽  
Daniela Traini ◽  
...  

l-Leucine modified voriconazole spray dried micropartcles.


2005 ◽  
Vol 187 (11) ◽  
pp. 3864-3868 ◽  
Author(s):  
Fabien Gaboriaud ◽  
Sidney Bailet ◽  
Etienne Dague ◽  
Frédéric Jorand

ABSTRACT The nanomechanical properties of gram-negative bacteria (Shewanella putrefaciens) were investigated in situ in aqueous solutions at two pH values, specifically, 4 and 10, by atomic force microscopy (AFM). For both pH values, the approach force curves exhibited subsequent nonlinear and linear regimens that were related to the progressive indentation of the AFM tip in the bacterial cell wall, including a priori polymeric fringe (nonlinear part), while the linear part was ascribed to compression of the plasma membrane. These results indicate the dynamic of surface ultrastructure in response to changes in pH, leading to variations in nanomechanical properties, such as the Young's modulus and the bacterial spring constant.


2006 ◽  
Vol 514-516 ◽  
pp. 1598-1602 ◽  
Author(s):  
Sergio Graça ◽  
Rogerio Colaço ◽  
Rui Vilar

When atomic force microscopy is used to retrieve nanomechanical surface properties of materials, unsuspected measurement and instrumentation errors may occur. In this work, some error sources are investigated and operating and correction procedures are proposed in order to maximize the accuracy of the measurements. Experiments were performed on sapphire, Ni, Co and Ni-30%Co samples. A triangular pyramidal diamond tip was used to perform indentation and scratch tests, as well as for surface visualization. It was found that nonlinearities of the z-piezo scanner, in particular the creep of the z-piezo, and errors in the determination of the real dimensions of tested areas, are critical parameters to be considered. However, it was observed that there is a critical load application rate, above which the influence of the creep of the z-piezo can be neglected. Also, it was observed that deconvolution of the tip geometry from the image of the tested area is essential to obtain accurate values of the dimensions of indentations and scratches. The application of these procedures enables minimizing the errors in nanomechanical property measurements using atomic force microscopy techniques.


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