Systems and methods for detection and analysis of biological species

1. A method for detecting a biological molecule, comprising:

(a) activating a sensor comprising a circuit having at least two electrodes by applying at least two different voltage waveforms with different frequencies to said at least two electrodes, measuring one or more first signals associated with first impedances of said circuit, and deriving one or more first electrical parameters from said one or more first signals, wherein each of said first impedances is associated with one of said at least two different voltage waveforms;

(b) bringing a solution comprising said biological molecule adjacent to said sensor under conditions sufficient to permit said biological molecule to couple to a support proximate to said at least two electrodes;

(c) applying said at least two different voltage waveforms to said circuit having said at least two electrodes, measuring one or more second signals associated with second impedances of said circuit, and deriving one or more second electrical parameters from said one or more second signals, wherein each of said second impedances is associated with one of said at least two different voltage waveforms; and

(d) comparing at least one of said one or more first electrical parameters with at least one of said one or more second electrical parameters to detect a presence of said biological molecule.

2. The method of claim 1 , wherein said biological molecule comprises a nucleotide base, a nucleic acid, a protein or a peptide.

3. The method of claim 1 , wherein said biological molecule is coupled to said support through a linker molecule.

4. The method of claim 1 , wherein said support is a bead.

5. The method of claim 1 , wherein said at least two different voltage waveforms comprise frequencies along a continuous frequency sweep.

6. The method of claim 1 , wherein said first signals or said second signals comprise a first current and a second current each associated with one of said at least two different voltage waveforms.

7. The method of claim 6 , further comprising deriving said first impedances or said second impedances from said first current and said second current.

8. The method of claim 1 , wherein one or more of said at least two electrodes is positioned within a Debye layer comprising said support, and wherein said first impedances or said second impedances are associated with said Debye layer.

9. The method of claim 1 , wherein in (b), said at least two electrodes are exposed to said solution.

10. The method of claim 1 , wherein said biological molecule comprises a nucleotide base, and wherein said biological molecule is a component of a nucleic acid sequencing reaction.

11. The method of claim 1 , wherein at least one of said at least two different voltage waveforms comprises a square wave.

12. The method of claim 1 , wherein said one or more first electrical parameters or said one or more second electrical parameters comprise one or more members selected from the group consisting of: (i) a resistance associated with a support proximate to at least one of said at least two electrodes; (ii) a fluid capacitance associated with a fluid proximate to said at least two electrodes; and (iii) an electrode capacitance associated with one or more of said at least two electrodes.

13. The method of claim 1 , wherein said at least two electrodes comprise a transmitter electrode and a receiver electrode, and wherein said first signals and said second signals are generated using an electrical flow path directed from said transmitter electrode to said receiver electrode.

14. The method of claim 13 , wherein prior to (a) said transmitter electrode and said receiver electrode are electrically isolated, and wherein activating said sensor in (a) comprises forming said electrical flow path.

15. The method of claim 1 , wherein the one or more second electrical parameters comprise a combined resistance associated with said support and said biological molecule.

16. The method of claim 1 , wherein at least one of said at least two different voltage waveforms comprises multiple frequencies, multiple phases, or a combination thereof.

17. The method of claim 1 , wherein said at least two different voltage waveforms comprise frequencies in a range of about 100 kilohertz to 1 megahertz.

18. The method of claim 1 , wherein deriving one or more first electrical parameters from said one or more first signals comprises solving a system of equations to calculate a first admittance of said circuit using said one or more first signals, and wherein deriving one or more second electrical parameters from said one or more second signals comprises solving said system of equations to calculate a second admittance of said circuit using said one or more second signals.