A method of identifying a substrate for a protease, the method comprising the steps of: a. contacting a protease to one of a first microarray and a second microarray, each of the first microarray and the second microarray having a plurality of features, the first microarray and the second microarray having the same plurality of features, each feature comprising one or more sequences including a unique candidate protease substrate, the one or more sequences being linked to a solid support and further linked to a reporter peptide, wherein: the at least one sequence has a formula: [R 1]-[L 1]-[Z 1]-[X 1]-[Z 2]-[L 2] wherein: R 1 is a reporter peptide, L 1 and L 2 are each a spacer, Z 1 and Z 2 are independently selected from a peptide sequence having between 0 to 3 amino acids, and X 1 is a peptide having a defined sequence of from 5 to 15 amino acids; b. contacting a detectable element to each of the first microarray and the second microarray to allow binding of the detectable element to the reporter peptide in the at least one sequence in each of the features of the first microarray and the second microarray; c. detecting a first signal resulting from binding of the detectable element to the reporter peptide in the at least one sequence in each of the features of the first microarray and a second signal resulting from binding of the detectable element to the reporter peptide in the at least one sequence in each of the features of the second microarray; d. comparing the first signal resulting from binding to the first microarray and the second signal resulting from binding to the second microarray to identify a difference in the first signal and the second signal; e. identifying at least one candidate protease substrate in the features identified in step d as a substrate for the protease, wherein the reporter peptide is a peptide binder to a protein and the detectable element is the protein to which the peptide binder specifically binds. a. contacting a protease to one of a first microarray and a second microarray, each of the first microarray and the second microarray having a plurality of features, the first microarray and the second microarray having the same plurality of features, each feature comprising one or more sequences including a unique candidate protease substrate, the one or more sequences being linked to a solid support and further linked to a reporter peptide, wherein: the at least one sequence has a formula: [R 1]-[L 1]-[Z 1]-[X 1]-[Z 2]-[L 2] wherein: R 1 is a reporter peptide, L 1 and L 2 are each a spacer, Z 1 and Z 2 are independently selected from a peptide sequence having between 0 to 3 amino acids, and X 1 is a peptide having a defined sequence of from 5 to 15 amino acids; R 1 is a reporter peptide, L 1 and L 2 are each a spacer, Z 1 and Z 2 are independently selected from a peptide sequence having between 0 to 3 amino acids, and X 1 is a peptide having a defined sequence of from 5 to 15 amino acids; b. contacting a detectable element to each of the first microarray and the second microarray to allow binding of the detectable element to the reporter peptide in the at least one sequence in each of the features of the first microarray and the second microarray; c. detecting a first signal resulting from binding of the detectable element to the reporter peptide in the at least one sequence in each of the features of the first microarray and a second signal resulting from binding of the detectable element to the reporter peptide in the at least one sequence in each of the features of the second microarray; d. comparing the first signal resulting from binding to the first microarray and the second signal resulting from binding to the second microarray to identify a difference in the first signal and the second signal; e. identifying at least one candidate protease substrate in the features identified in step d as a substrate for the protease, wherein the reporter peptide is a peptide binder to a protein and the detectable element is the protein to which the peptide binder specifically binds.