1. O.S. Larionovad, V.A. Feodorovaa
Amplification of output signal of laser scanning speckle-microscope using gold nanoparticles: detection of a single chlamydial cell in a clinical sample
O.V. Ulianovaa, N.N. Filonovaa, I.A. Subbotinaa, S.S. Ulyanova, b, L.A. Dykmanc, S.S. Zaytseva, Yu.V. Saltykova,
O.S. Larionovad, V.A. Feodorovaa

2. AFFILIATION
a Federal Research Center for Virology and Microbiology, Branch in Saratov RUSSIA
b Saratov State University, RUSSIA
c Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences (IBPPM RAS), RUSSIA
D Saratov State Agrarian University, RUSSIA

3. ABSTRACT
Combined system “Chlamydia trachomatis bacterial cell”-“monoclonal antibody”-“gold nanoparticle” has been used as a complicated scattering element in the case of formation of biospeckles with a small number of scatterers. It has been demonstrated theoretically and experimentally, that signal of speckle microscope is increased drastically in the presence of gold nanoparticles. It has been demonstrated the unique possibility of detection of a single C. trachomatis cell in a clinical sample.

4. Demonstration of principles of speckle-microscopy

5. General view of speckle-microscope

6. Sample (with C. trachomatis bacterial cell, fixed on the microscope slide) on the speckle-microscope

7. Seria of three realizations of output signal of scanning microscope
Scanning samples (fixed on the glass) containing C. trachomatis cells, connected with the conjugate “Chlamydial monoclonal antibody + gold nanopartickles (diameter = 20 nm)” (CT-Mab-Au)

8. #1
Appearance of peaks corresponds to the moment of scanning of immune nanocomplex CT-Mab-Au by strongly focused laser beam

9. #2 Appearance of peaks corresponds to the moment of scanning
of immune nanocomplex CT-Mab-Au by strongly focused laser beam

10. #3 Appearance of peaks corresponds to the moment of scanning of
immune nanocomplex CT-Mab-Au by strongly focused laser beam

11. Seria of three smoothed spectra obtained for three realizations of output signal of scanning microscope. Shapes of spectra are identical.
Scanning samples (fixed on the glass) containing
with C. trachomatis cells, connected with conjugate
Mab-Au of 20 nm

12. #1

13. #2

14. #3

15. Testing of complexes, which contain and do not contain nanoparticles/(CT-Mab-Au)

16. Motionless sample, containing only CT cells (without immune complexes of chlamydial monoclonal antibody (Mab) with gold nanoparticles (Au))
This signal can be considered as a pure noise of measuring set-up.
No any peaks, generated as a result of light scattering by Mab labelled
with Au, are shown up in output signal.

17. Scanning of CT cells, connected with Mab and nanoparticles
Peaks, produces by laser light scattering by CT-Mab-Au,
are shown up in output signal

18. Scanning of CT cells, which do not bind with Mab and gold nanopatickes
No peaks, produces by laser light scattering by CT-Mab-Au, are observable

19. Summary It is clearly demonstrated, that in the case when CT cells are
by Mab labelled with gold nanoparticles,
output signal of speckle microscope
is essentially enhanced.
It opens the way of detection of a single CT bacterial cell
in the analyzing samples.

20. This research has been supported by Russian Science Foundation,
ACKNOWLEDGEMENT
This research has been supported by Russian Science Foundation,
grant #

21. THANK YOU FOR ATTENTION!