A method of detecting an analyte of interest, the method comprising: functionalizing an integrated circuit comprising an exposed surface carrying a plurality of sensing electrodes, by: providing a solution comprising a plurality of biomolecule receptor molecules (30, 30') for selectively binding to different analytes of interest (40, 40'); and exposing said surface to said solution, thereby forming a random distribution of said receptor molecules on the respective sensing electrodes, and such that a first sensing electrode comprises at its surface a first receptor molecule for selectively binding to a first analyte of interest and a second sensing electrode comprises at its surface a second receptor molecule for selectively binding to a second analyte of interest; exposing said functionalized integrated circuit to a sample potentially comprising at least one of the first analyte and the second analyte of interest; providing a first bead having a first electrical signature attached to a first molecule (30, 40, 45) having a conformation or an affinity for binding to the first sensing electrode that is dependent on the presence of the first analyte in said sample; providing a second bead having a second electrical signature attached to a second molecule (30', 40', 45') having a conformation or an affinity for binding to the second sensing electrode that is dependent on the presence of the second analyte in said sample; and determining the presence of the electrical signature of the first bead on the first sensing electrode and/or the presence of the electrical signature of the second bead on the second sensing electrode. functionalizing an integrated circuit comprising an exposed surface carrying a plurality of sensing electrodes, by: providing a solution comprising a plurality of biomolecule receptor molecules (30, 30') for selectively binding to different analytes of interest (40, 40'); and exposing said surface to said solution, thereby forming a random distribution of said receptor molecules on the respective sensing electrodes, and such that a first sensing electrode comprises at its surface a first receptor molecule for selectively binding to a first analyte of interest and a second sensing electrode comprises at its surface a second receptor molecule for selectively binding to a second analyte of interest; providing a solution comprising a plurality of biomolecule receptor molecules (30, 30') for selectively binding to different analytes of interest (40, 40'); and exposing said surface to said solution, thereby forming a random distribution of said receptor molecules on the respective sensing electrodes, and such that a first sensing electrode comprises at its surface a first receptor molecule for selectively binding to a first analyte of interest and a second sensing electrode comprises at its surface a second receptor molecule for selectively binding to a second analyte of interest; exposing said functionalized integrated circuit to a sample potentially comprising at least one of the first analyte and the second analyte of interest; providing a first bead having a first electrical signature attached to a first molecule (30, 40, 45) having a conformation or an affinity for binding to the first sensing electrode that is dependent on the presence of the first analyte in said sample; providing a second bead having a second electrical signature attached to a second molecule (30', 40', 45') having a conformation or an affinity for binding to the second sensing electrode that is dependent on the presence of the second analyte in said sample; and determining the presence of the electrical signature of the first bead on the first sensing electrode and/or the presence of the electrical signature of the second bead on the second sensing electrode.