Lytic peptide biosensor and methods of making and using the same

A method of detecting a chronic condition or disorder in a subject, wherein the chronic condition or disorder is characterized by the presence of an antimicrobial membrane lytic peptide, the method comprising:

• inducing bacterial cells for 1 hour to express an enzyme;
• lyophilizing the bacterial cells;
• obtaining a sample from the subject, wherein the sample is selected from blood, saliva, urine, or combinations thereof;
• contacting the lyophilized bacterial cells with the sample, wherein the sample comprises an amount of the antimicrobial membrane lytic peptide;
• contacting the lyophilized bacterial cells with a substrate that produces a color change in the presence of the enzyme released from the bacterial cells;
• incubating the bacterial cells for a desired amount of time during which time the enzyme is being released to interact with a colorless substrate;
• detecting the presence of the membrane lytic peptide in the sample by colorimetric analysis of the color change in the sample,
• wherein the color change is based on the lytic action of the membrane lytic peptide on the bacterial cell membrane, creating pores that enable the release of the enzyme;
• wherein the presence of the membrane lytic peptide indicates the presence of the chronic condition or disorder in the subject;
• and
• wherein the total time from contacting the lyophilized bacterial cells with the sample to detecting is 0.5-3.5 hours.