Electrochemical device

An electrochemical microsensor comprising an array of working microelectrodes, the array of working microelectrodes comprising:

• one or more bare microelectrodes;
• one or more thick film-coated microelectrodes, optionally with conductive additive incorporated into the coating, selected from the group consisting of polysaccharide-coated microelectrodes and platinum black-coated microelectrodes;
• one or more thin film-coated microelectrodes selected from the group consisting of reduced graphene oxide-coated microelectrode and transition metal chalcogenide-coated microelectrodes, wherein the transition metal chalcogenide is selected from electrodeposited MoS2 and electrodeposited WS2;
• wherein:
• the electrochemical microsensor further comprises a counter electrode and one or more reference microelectrode(s);
• the one or more thick film-coated microelectrodes comprise:
• one or more polysaccharide-coated microelectrodes;
• one or more polysaccharide-coated microelectrodes with conductive additives incorporated into the coating;
• and
• one or more platinum black-coated microelectrodes;
• the one or more thin film-coated microelectrodes comprise:
• one or more reduced graphene oxide-coated microelectrodes;
• one or more MoS2-coated microelectrodes, wherein the MoS2 coating is an electrodeposited MoS2 film;
• and
• one or more WS2-coated microelectrodes, wherein the WS2 coating is an electrodeposited WS2 film;
• and
• the one or more reference microelectrode(s) is an Ag/AgCl microelectrode;
• the electrochemical microsensor comprising N microelectrodes, wherein at least one of the N microelectrodes is a disc-shaped counter electrode of diameter in the range from 200 to 500 μm and a total of N-1 working and reference microelectrodes are placed evenly around the perimeter of the at least one disc-shaped counter electrode, equidistantly from the center of the at least one disc-shaped counter electrode, wherein the diameter of each individual working and reference microelectrodes is from 10 to 100 μm, wherein each of the N-1 working and reference microelectrodes is individually confined within a microchamber, which corresponds in size and shape to the microelectrode, leaving the upper surface of the microelectrode accessible to a solution or liquid sample, and the entire set of N microelectrodes is encircled by the walls of a larger microchamber, defining a receptable for holding a solution or liquid sample.