AFM Specific Identification of Bacterial Cell Fragments on Biofunctional Surfaces
Evgeniy V Dubrovin*, 1, Galina N Fedyukina2, Sergey V Kraevsky3, Tatiana E Ignatyuk3, Igor V Yaminsky1, Sergei G Ignatov2
1 M.V. Lomonosov Moscow State University, 1/2 Leninskie gory, Moscow, 119991, Russia
2 State Research Center for Applied Microbiology and Biotechnology, Obolensk, 142279, Russia
3 Institute for Theoretical and Experimental Physics, 25 Bolshaya Cheremushkinskaya, Moscow, 117218, Russia
Biointerfaces with a highly sensitive surface designed for specific interaction with biomolecules are essential approaches for providing advanced biochemical and biosensor assays. For the first time, we have introduced a simple AFM-based recognition system capable of visualizing specific bacterial nanofragments and identifying the corresponding bacterial type. For this we developed AFM-adjusted procedures for preparing IgG-based surfaces and subsequently exposing them to antigens. The AFM images reveal the specific binding of Escherichia coli cell fragments to the prepared biofunctional surfaces. Moreover, the binding of bacterial cell fragments to the affinity surfaces can be characterized quantitatively, indicating a 30-fold to 80-fold increase in the quantity of bound antigenic material in the case of a specific antigen-antibody pair. Our results demonstrate significant opportunities for developing reliable sensing procedures for detecting pathogenic bacteria, and the cell can still be identified after it is completely destroyed.
Keywords: Atomic force microscopy, affine surfaces. biosensors, Escherichia coli, antibodies.
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* Address correspondence to this author at the M.V. Lomonosov Moscow State University, Leninskie gory, 1-2, 119991 Moscow, Russia; Tel: +7 495 926 3743; Fax: +7 495 939 2988; E-mail: firstname.lastname@example.org