Association of molecules with electrodes of an array of electrodes

A method of modifying electrodes of an array of electrode pairs, each electrode pair comprising a first and second electrode, the first and second electrodes of the electrode pairs to be modified by binding at least one respective probe molecule thereto, wherein, prior to being modified, at least one respective, protective molecule overlays each of the first and second electrodes of at least one electrode pair such that the at least one respective, protective molecule inhibits probe molecules from binding to the first and second electrodes, the method comprising:

• (a) dissociating the at least one protective molecule from the first electrode of at least one electrode pair without dissociating the at least one protective molecule from the second electrode of the at least one electrode pair, the first and second electrodes of the at least one electrode pair being spaced apart by less than 1000 Angstroms;
• and
• (b) contacting the first and second electrode of at least one electrode pair of the array of electrode pairs with a liquid comprising a first probe molecule;
• and
• wherein, for at least one first electrode of at least one electrode pair subjected to the step of (b) contacting, the first electrode is also subjected to the step of (a) dissociating, wherein the first probe molecule of the liquid binds to the first electrode.

A method of modifying electrodes of an array of electrodes, the electrodes to be modified by binding at least one respective probe molecule thereto, the method comprising:

• (a) addressing at least one electrode of the array of electrodes with a dissociation potential;
• (b) contacting electrodes of the array of electrodes with a liquid comprising a probe molecule;
• (c) contacting electrodes of the array of electrodes with a liquid comprising a protective molecule;
• and
• wherein at least a first electrode subjected to the step of (a) addressing is (i) subjected to the step of (b) contacting while not concurrently being subjected to the step of (a) addressing and (ii) subjected to the step of (c) contacting while not concurrently being subjected to the step of (a) addressing, and wherein at least one probe molecule and at least one protective molecule bind to the first electrode.

A method of forming an electrical connection between a first electrode and a second electrode of an electrode pair:

• binding a first molecule to the first electrode, the first molecule comprising a first single stranded polynucleotide;
• binding a second molecule to the second electrode, the second molecule comprising an intercalating group configured to intercalate with double stranded polynucleotides;
• and
• contacting the electrode pair with a second single stranded polynucleotide at least partially complementary to the first polynucleotide, wherein the first and second polynucleotides form a duplex region and the intercalating group intercalates with the duplex region thereby forming the electrical connection between the first and second electrodes.

An apparatus for preparing an array of modified surfaces, comprising:

• a device configured to at least:
• contact electrodes of each of a number N subsets of electrodes an array of electrodes with a respective liquid, wherein each liquid comprises a respective, different compound and N is an integer greater than 1;
• and
• for each subset of the N subsets of electrodes, modify an electrical potential between at least a first electrode of the subset of electrodes and a reference electrode, whereby the respective compound of the fluid contacting the first electrode binds to the first electrode.

A sensor, comprising:

• a substrate comprising a first electrode pair comprising first and second electrodes;
• a first molecule bound with the first electrode, the first molecule comprising a first polynucleotide;
• a second molecule bound with the second electrode, the second molecule comprising a group configured to intercalate with double stranded polynucleotide compounds;
• and
• wherein, upon contacting the first electrode pair with a liquid comprising a second polynucleotide sequence at least partially complementary to the first polynucleotide sequence, the first and second polynucleotide sequences form a duplex region and the intercalating portion intercalates with the duplex region, thereby modifying an electrical characteristic of the first and second electrodes whereby the presence of the at least partially second polynucleotide may be determined.