1.  ORIENTED IMMOBILIZED ANTIBODIES IN SERS-BASED IMMUNOASSAY AGAINST BOVINE LEUKEMIA VIRUS Author: Julija Baniukevic, doctoral candidate of Nanotechnology Research Center, Chemistry Faculty, Vilnius university, Lithuania 1 st International Baku Forum

2. Outline  What are the immunosensors?  Research object  The ways to achieve the goal  Conclusions  Nanoprospectives

3. What are the immunosensors?

4. Ab + Ag ↔ AbAg Sharma SK, Seghal N, Kumar A. Biomolecules for development of biosensors and their applications. Current Applied Physics. 2003; 3: 307-316. Wang J. Analytical electrochemistry. 2nd ed. New York: Wiley-VCH: 2000; 52-54, 183-188

5. Antibodies and their structure

6. Bovine leukemia virus structure Reverse transcriptase gp51/gp30 RNA p15 Integrase Lipids layer p24 Nermut MV, Hockley DJ. Comparative morphology and structural classification of retroviruses. Curr Top Microbiol Immunol 1996; 214: 1-22.

7. Antibody-antigen interaction

8. Karyakin AA, Presnova GV, Rubtsova MY, Egorov AM. Oriented immobilization of antibodies onto the gold surfaces via their native thiol groups. Anal Chem 2000; 72: 3805-3811 Immunosensor design

9. Immunosensors devices

10. Schematic illustration of SERS-based sandwich immunoassay for BLV gp 51 detection

11. Capturing efficiency of antibody on MNP-Au and retained antigen binding efficiency measured with HPLC.

12. SERS spectra of A) BLV antigen gp 51; B) Raman label and anti– gp 51 labeled Au-NRs (TNB-labeled anti– gp 51-Au-NRs) in the sandwich immunoassay without antigen; C) Raman Raman label and anti– gp 51 labeled Au-NRs (TNB-labeled anti– gp 51-Au-NRs) with 0.1 mg mL-1 of antigen in the sandwich immunoassay.

13. Why is it so important?

14. Bovine leukemia virus consequences http://www.vetmed.ucdavis.edu/vetext/INF-DA/INF-DA_BovineLeukemia.html

15. Conclusions The developed SERS-based immunoassay based on oriented immobilisation of antibodies on MNP-Au and magnetic separation after interaction with analyte presents an indirect, less time consuming and easy-to-use method for antigen detection. A good linear correlation (R 2 =0.9983) between the SERS signal and antigen concentration was obtained within the range of 0-0.06 mg mL -1 of gp51 concentration. The sensitivity of the developed assay was investigated and the LOD and LOQ of the proposed method for gp51 detection were found to be 0.95 µg mL -1 and 3.14 µg mL -1, respectively.

16. Conclusions This method was successfully applied for the detection of bovine leukemia virus antigen gp51 in a milk samples in a rapid, reliable and selective manner. Recoveries of the proposed method in real samples were in the range of 85.5 – 100 %. It was found that better recovery was achieved by increasing the concentration of analyte. The proposed SERS-based immunoassay using MNP-Au can be applied for the detection of other analytes.

17. Enhancing public engagement with nanotechnology  NANOPINION, which launched on May 1, 2012, is a €2 million, 30 month project bringing together 17 partners from 11 countries. Investigation of opinion will use an innovative multi-stranded approach, focusing on dialogue. It will include surveys, social media, street labs, and events in public spaces such as science centres and shopping streets. It will provide access to new materials on the risks and benefits of nanotechnologies.

18. www.nanopinion.eu

19. Thank you for your attention