Detection of target analytes using particles and electrodes
The invention relates to the use of particles comprising binding ligands and electron transfer moieties (ETMs). Upon binding of a target analyte, a particle and a reporter composition are associated and transported to an electrode surface. The ETMs are then detected, allowing the presence or absence of the target analyte to be determined.
1. A composition comprising:
a) a substrate comprising an array of working electrodes, wherein each electrode comprises a first binding ligand;
b) a plurality of colloids, each comprising:
i) a second binding ligand; and
ii) an electron transfer moiety; and
c) a detector capable of detecting a voltage associated with electron transfer from said electron transfer moiety.
2. The composition of claim 1 wherein said plurality of colloids further comprise a self-assembled monolayer.
3. The composition of claim 2 wherein said self-assembling monolayer comprises an alkyl chain.
4. The composition of claim 1 wherein said substrate is a printed circuit board.
5. The composition according to claim 1 wherein said electrodes are gold.
6. The composition according to claim 1 wherein said electron transfer moiety is a transition metal complex.
7. The composition according to claim 6 wherein said transition metal complex is ferrocene.
8. The composition according to claim 1 wherein said first binding ligand is a first nucleic acid and said second binding ligand is a second nucleic acid.