System and method for trapping and measuring a charged particle in a liquid

1. A system for trapping a charged particle in a trapping volume comprising:

(a) at least three confining electrodes distributed around the trapping volume;

(b) a liquid container adapted to hold a liquid carrying the charged particle between the at least three confining electrodes; and

(c) a power source electrically connected to the at least three confining electrodes, wherein the power source is capable of applying a time-varying periodic voltage bias between the at least three confining electrodes for creation of a time-varying periodic multipole electric potential in the trapping volume, wherein the multipole electric potential is at least a quadrupole.

2. The system of claim 1 , wherein the liquid container is fluidly connected to a microfluidic channel for supplying liquid to the liquid container.

3. The system of claim 1 , wherein the trapping volume is microscopic.

4. The system of claim 1 , wherein the trapping volume is nanoscopic.

5. The system of claim 1 , wherein the liquid container is adapted to hold a liquid solution comprising an electrolyte.

6. The system of claim 1 , wherein the at least three confining electrodes are N confining electrodes positioned around the trapping volume so that the multipole electric potential in the trapping volume is orthogonal to a longitudinal axis of the trapping volume, wherein N is an even whole number of four or greater.

7. The system of claim 6 , wherein the N confining electrodes are coplanar in a plane orthogonal to the longitudinal axis of the trapping volume.

8. The system of claim 7 , further comprising:

(d) two electrodes arranged along the longitudinal axis of the trapping volume so that the trapping volume is between them; and

(e) a power source electrically connected to the two electrodes arranged along the longitudinal axis of the trapping volume, wherein the power source is capable of applying a voltage bias for controlling the movement of the charged particle along the longitudinal axis of the trapping volume.

9. A system for trapping a charged particle comprising:

(a) two longitudinally confining electrodes arranged along a longitudinal axis;

(b) a transversely confining electrode encircling the region between the two longitudinally confining electrodes transversely to the longitudinal axis;

(c) a liquid container adapted to hold a liquid carrying the charged particle between the two longitudinally confining electrodes and the transversely confining electrode; and

(d) a power source electrically connected to the longitudinally confining electrodes and the transversely confining electrode, wherein the power source is capable of applying a time-varying periodic voltage bias to create a time-varying quadrupole electric potential in the trapping volume.

10. The system of claim 9 , wherein the liquid container comprises a nanopore.

11. The system of claim 9 , further comprising a sensor adjacent to the trapping volume for measuring a property of the charged particle.

12. The system of claim 11 , wherein the property measured by the sensor adjacent to the trapping volume is the transverse conductivity.

13. The system of claim 12 , wherein the charged particle is a biomolecule.

14. A method of trapping a charged particle in a trapping volume comprising:

(a) positioning a liquid containing a charged particle between at least three confining electrodes;

(b) applying a time-varying periodic voltage bias to the at least three confining electrodes distributed around the trapping volume;

(c) generating a multipole electric potential in the trapping volume, wherein the multipole electric potential is at least a quadrupole; and

(d) trapping the charged particle within the trapping volume.

15. The method of claim 14 , wherein the at least three confining electrodes are N confining electrodes positioned around the trapping volume so that the multipole electric potential in the trapping volume is orthogonal to a longitudinal axis of the trapping volume, wherein N is an even whole number of four or greater.

16. The method of claim 15 , wherein the N confining electrodes are coplanar in a plane orthogonal to the longitudinal axis of the trapping volume.

17. The method of claim 14 , further comprising flowing the liquid containing the charged particle through a microfluidic channel.

18. The method of claim 14 , wherein the liquid containing the charged particle is an electrolytic solution.

19. The method of claim 14 , further comprising measuring a property of the charged particle.