Carbon hybrid nanomaterials
We fabricate, analyze and use different types of carbon hybrid nanomaterials for various analytical applications. Typically we utilize diamond-like carbon (DLC) thin films as our substrates and then we integrate, in a controlled manner, other more active allotropes of carbon, such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), nanodiamonds and chemically reduced graphene oxide, on top of these thin films to achieve desired properties for the hybrid material. Our main application area is the electrochemical detection of various biomolecules, but these materials can be utilized for other purposes as well. We extensively combine experimental work with detailed atomistic simulations, mainly based on the density functional theory (DFT) approaches.
Carbon hybrid nanomaterials
Multi-walled carbon nanotubes (MWCNTs) grown directly on top of thin films of DLC
Results for a-C surfaces of different densities. Rows from top to bottom: (i) relaxed supercells where C atoms are (yellow) large ball and H atoms are (blue) small balls, sticks indicate bonds; (ii) chain analysis for the different systems, as explained in Section 2.2 (note the different scales between samples); (iii) local density averaged along the direction perpendicular to the surface normal and its decomposition into sp3 and sp2 contributions; (iv) PDOS averaged for all the atoms contained within a certain region below the surface/vacuum interface. The structures were plotted with XCrysDen. [From: Caro M., Zoubkoff R, Lopez-Acevedo O., and Laurila T, “Atomic and electronic structure of tetrahedral amorphous carbon surfaces from density functional theory: properties and simulation strategies”, Carbon, 77, pp. 1168-1182, (2014).]
Publications (since 2013):
Laurila T., Sainio S., Jiang H., Koskinen J., Koehne J. and Meyyappan M., “The role of extra carbon source during the pre-annealing stage in the growth of carbon nanofibers”, Carbon, 100, 351-354, (2016).
Sainio S., Jiang H., Caro M.A., Koehne J., Lopez-Acevedo O, Koskinen J., Meyyappan M., and Laurila T.,“Structural morphology of carbon nanofibers grown on different substrates”, Carbon, 98, 343-351, (2016).
Laurila T., Sainio S., Jiang H., Palomäki T., Pitkänen O., Kordas K., and Koskinen J., ” Multi-walled carbon nanotubes (MWCNTs) grown directly on tetrahedral amorphous carbon (ta-C): An interfacial study”, Diamond and Related Materials, 56, pp. 54-59, (2015).
Protopopova V., Iyer A., Wester N., Kondrateva A., Sainio S., Palomäki T., Laurila T., Mishin M., and Koskinen J.., “Ultrathin undoped tetrahedral amorphous carbon films: The role of the underlying titanium layer on the electronic structure”, Diamond and Related Materials, 57, pp. 43-52, (2015).
Protopopova V., Wester N.,. Caro M., Gabdullin P., Palomäki T., Laurila T. and Koskinen J. “Ultrathin undoped tetrahedral amorphous carbon films: Thickness dependence of the electronic structure and implications to electrochemical behavior”, Physical Chemistry Chemical Physics, 17, pp. 9020-9031, (2015).
Sainio S., Palomäki T., Tujunen N., Protopopova V., Koehne J., Kordas K., Koskinen J., Meyyappan M., and Laurila T., “Integrated carbon nanostructures for detection of neurotransmitters”, Molecular Neurobiology, 52, (2), pp. 859-866, (2015).
Caro M., Zoubkoff R, Lopez-Acevedo O., and Laurila T, “Atomic and electronic structure of tetrahedral amorphous carbon surfaces from density functional theory: properties and simulation strategies”, Carbon, 77, pp. 1168-1182, (2014).