Nanostructured Imaging Surface Plasmon Resonance Optical Biosensing

Transcription

1 Nanostructured Imaging Surface Plasmon Resonance Optical Biosensing Sweccha Joshi, Teris A. van Beek, Han Zuilhof, Michel W.F. Nielen MicroNano conference December This research receives funding from the Netherlands Organisation for Scientific Research (NWO) in the framework of the Technology Area COAST (project nr ) with Wageningen University, VU Amsterdam, RIKILT, Heineken, Synthon, Technex, EuroProxima, Waterproef as partners and Plasmore and Bionavis as associated partners.

2 Surface Plasmon Resonance (SPR) biosensors Optics Chip Fluidics Affinity based optical biosensor Fast, sensitive and label free detection, realtime information on the binding kinetics 2

3 Imaging SPR Can define regions of interest (ROI) ROI multiple interactions can be monitored in parallel Reference ROI inside or outside the chip 3

4 Benchtop SPR SPR instruments Benchtop ispr smaller 8-11 lighter 7-12 cheaper Prototype portable ispr Aim: Model assay for in-field detection of mycotoxins in food 4

5 Nanostructured ispr chips Atomic Force Microscopy (AFM) Gold ring Flat gold Scanning Electron Microscopy (SEM) Residual polystyrene bead PMMA Flat gold Gold ring Act as nanograting no prisms Nanostructured ispr 5

6 Surface chemistry on ispr chips For immobilization of ligands Non-specific interactions (fouling) false positives Worse in the case of complex matrices (real samples) To use antifouling chemistries to increase specificity and selectivity, easier regeneration Most popular carboxymethylated dextran (Biacore) Oligo and polyethylene glycols Zwitterionic polymers 6 Sweccha Joshi - Wageningen University

7 Antifouling Chemistry Grafting to Grafting from 7

8 S 2p Au 4f CPS CPS N 1s C 1s O 1s C 1s Surface characterization X-ray photoelectron 13th block id: 3, 1, 1, 1 spectroscopy (XPS) x 10 3 Name C1s N1s O1s S2p Au4f Pos At% x 10 2 Name C1s C1s C1s Pos At% C-O/N/S/Br C=O 14th block id: 3, 1, 1, 2 C-C Binding Energy (ev) CasaXP S (This string can be edited in CasaXPS.DEF/P rintfootnote.txt) Binding Energy (ev) CasaXP S (This string can be edited in CasaXPS.DEF/P rintfootnote.txt) Survey scan Relative atomic percentage of elements on the surface Thickness of layer ratio of C:Au Narrow scan Relative percentage of a specific element present in different chemical environment 8

9 Relative abundance Relative Abundance Relative abundance Surface characterization Direct Analysis in Real Time-High Resolution Mass Spectrometry (DART- HRMS) PFP-nano gold # RT: AV: 8 SB: 7 T: FTMS + p NSI Full ms [ ] [C 6 F 5 OC(=O) (CH 2 ) 15 -S H 2 ] mmu m/z m/z PFP-nano gold-2 # RT: AV: 70 SB: 10 T: FTMS - p NSI Full ms [ ] 100 [C 6 F 5 O] m/z mmu m/z Manova, R. K., Joshi, S. et al., Anal. Chem. 2014, 86,

10 Relative abundance Surface characterization Direct Analysis in Real Time-High Resolution Mass Spectrometry (DART-HRMS) EG1000-spiked on glass #66-88 RT: AV: 23 SB: , NL: 1.08E4 : FTMS + p NSI Full ms [ ] 100 PEG in solution p = m/z m/z 10

11 Relative abundance Surface characterization Direct Analysis in Real Time-High Resolution Mass Spectrometry (DART-HRMS) PEG3500-nano gold # RT: AV: 11 SB: NL: 2.78E4 T: FTMS + p NSI Full ms [ ] PEG on surface n = m/z m/z 11

12 Antifouling experiments Nanostructured ispr Washing with buffer Beer Amount of fouling Flowcell of the chip 12

13 Normalized response Comparison of antifouling properties 1,1 0,9 0,7 0,5 0,3 0,1-0,1 BSA Beer1 Beer2 Bare MHDA PEG1000 PEG3500 SBMA PEGMA 13

14 Relative response Nanostructured ispr Optical Biosensing - Proof-of-principle to show ligand-protein binding - ispr chip with PEG3500 was locally modified with biotin µg/ml streptavidin 2 - with biotin without biotin Time (s) - Binding of relatively small protein promising for biosensing application - S/N : 9 times less than benchtop SPR (Biacore), same as benchtop ispr (IBIS) 14

15 Relative response SPR response Relative response S 2p Au 4f CPS N 1s C 1s O 1s Nanostructured ispr chip Conclusions x SBMA Antifouling 13th block id: 3, 1, 1, Binding Energy (ev) CasaXP S (This string can be edited in CasaXPS.DEF/P rintfootnote.txt) 1.0 MHDA SBMA Bare Application Nanostructured ispr Optical Biosensing Time (s) SBMA Time (s) afb Time (s) Detection of mycotoxin in barley (FB1) S. Joshi, P. Pellacani, T. A. van Beek, H. Zuilhof and M. W. F. Nielen, Sens. Actuators, B 2015, 209, Questions!! 15

16 Nanostructured ispr chip preparation S. Giudicatti, A. Valsesia, F. Marabelli, P. Colpo and F. Rossi, Phys. Status Solidi A, 2010, 207,