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Pregled bibliografske jedinice broj: 510619

Quantitative nanomechanical mapping of marine diatom in seawater using peak force tapping AFM

Pletikapić, Galja; Berquand, Alexandre; Mišić Radić, Tea; Svetličić, Vesna
Quantitative nanomechanical mapping of marine diatom in seawater using peak force tapping AFM // Journal of phycology, 48 (2012), 1; 174-185 doi:10.1111/j.1529-8817.2011.01093.x (međunarodna recenzija, članak, znanstveni)

Quantitative nanomechanical mapping of marine diatom in seawater using peak force tapping AFM

Pletikapić, Galja ; Berquand, Alexandre ; Mišić Radić, Tea ; Svetličić, Vesna

Journal of phycology (0022-3646) 48 (2012), 1; 174-185

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Atomic force microscopy (AFM); Cylindrotheca closterium; deformation; diatom cell wall; elasticity; marine diatom; nanomechanical properties; Peak Force Tapping AFM; Young’s modulus

It is generally accepted that a diatom cell wall is characterized by a siliceous skeleton covered by an organic envelope essentially composed of polysaccharides and proteins. Understanding of how the organic component is associated with the silica structure provides an important insight into the biomineralization process and patterning on the cellular level. Using a novel AFM imaging technique (Peak Force Tapping) we characterized nanomechanical properties (elasticity and deformation) of a weakly silicified marine diatom Cylindrotheca closterium (Ehrenberg) Reimann & J.C. Lewin (strain CCNA1). The nanomechanical properties were measured over the entire cell surface in seawater at a resolution that was not achieved previously. The fibulae were the stiffest (200 MPa) and the least deformable (only 1nm). Girdle band region appeared as a series of parallel stripes characterized by two sets of values of Young’s modulus and deformation: one for silica stripes (43.7 MPa and 3.7 nm) and the other between the stripes (21.3 MPa, 13.4 nm). The valve region was complex with average values of Young’s modulus (29.8 MPa) and deformation (10.2 nm) with high standard deviations. After acid treatment, we identified 15 nm sized silica spheres in the valve region connecting raphe with the girdle bands. The silica spheres were neither fused together nor forming a nanopattern. A cell wall model is proposed with individual silica nanoparticles incorporated in an organic matrix. Such organization of girdle band and valve regions enables the high flexibility needed for movement and adaptation to different environments while maintaining the integrity of the cell.

Izvorni jezik

Znanstvena područja
Fizika, Kemija, Biologija


Projekt / tema
098-0982934-2744 - Površinske sile na atomskoj skali u istraživanju mora i nanotehnologiji (Vesna Svetličić, )

Institut "Ruđer Bošković", Zagreb

Časopis indeksira:

  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • Science Citation Index Expanded (SCI-EXP)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus