Scattering microscopy
A scattering microscopy arrangement uses a microscope to image an object comprising a surface. A light source emits illuminating light and a light detector detects light elastically scattered from the object. An electric potential is applied to the surface that affects the electrochemical properties of the object while imaging. The electric potential provides a contrast mechanism that improves the imaging and allows for characterisation of the object and/or the surrounding environment.
1. A method of performing scattering microscopy,
the method comprising imaging an object comprising a surface with a scattering microscope including a light source arranged to emit illuminating light and a light detector, the microscope being arranged to illuminate the object with the illuminating light and to detect light elastically scattered from the object with the light detector,
the method further comprising applying an electric potential to the surface that affects electrochemical properties of the object while imaging the object, the object being selected not to have a plasmon resonance frequency at wavelengths of the illuminating light and at the applied electric potential.
2. A method according to claim 1 , wherein an electric double layer forms at the object and the electric potential to the surface affects the electrochemical properties of the electric double layer.
3. A method according to claim 1 , wherein the surface is a surface of a dielectric material and the step of applying an electric potential to the surface comprises applying the electric potential capacitively through the dielectric material.
4. A method according to claim 1 , wherein the electric potential has an amplitude that is constant over a response period of the electrochemical properties of the object that are affected thereby.
5. A method according to claim 1 , wherein the method comprises applying plural different electric potentials to the surface, and detecting the light elastically scattered from a part of the object in respect of each electric potential for characterisation of that part of the object and/or a surrounding environment.
6. A method according to claim 1 , wherein the microscope is arranged so that the detected signal by the light detector is sensitive to amplitude of the light elastically scattered from the object.
7. A method according to claim 1 , wherein the microscope is an interferometric scattering microscope or a dark field scattering microscope.
8. A method according to claim 1 , wherein the microscope is arranged to output a two-dimensional image of the object.
9. A method according to claim 1 , wherein the light is ultraviolet light, visible light, or infrared light.
10. A method according to claim 1 , wherein the surface is a surface of a conductive material and the step of applying an electric potential to the surface comprises applying the potential to the conductive material.
11. A method according to claim 10 , wherein the conductive material is not a metal.
12. A method according to claim 1 , wherein the electric potential has an amplitude that changes over a period less than the response period of the electrochemical properties of the object that are affected thereby.
13. A method according to claim 12 , wherein the electric potential has an amplitude that is alternating over a period less than a response period of the electrochemical properties of the object that are affected thereby.
14. A method according to claim 1 , wherein the object further comprises at least one particle on the surface.
15. A method according to claim 14 , wherein the at least one particle has a mass of 5000 kDa or less.
16. A method according to claim 14 , wherein the at least one particle has a mass of 10 kDa or more.
17. A method according to claim 15 , wherein the at least one particle has a scattering cross section with respect to the illuminating light of 10 −17 m 2 or less.
18. A method according to claim 15 , wherein the at least one particle has a scattering cross section with respect to the illuminating light of 10 −26 m 2 or more.
19. A scattering microscopy arrangement, the microscopy arrangement comprising:
an object comprising a surface;
a microscope including a light source arranged to emit illuminating light and a light detector, the microscope being arranged to illuminate the object with the illuminating light and to detect with the light detector light elastically scattered from the object; and
a voltage source arranged to apply an electric potential to the surface that affects electrochemical properties of the object while imaging the object, the object being selected not to have a plasmon resonance frequency at wavelengths of the illuminating light and at the applied electric potential.