BBa_J04450 has a lac promoter and mRFP gene, thus E. coli harboring this plasmid will give red color when the bacteria were grown with lactose or IPTG. Oppositely, the expression of mRFP will be decreased when glucose was present in medium through a mechanism called catabolite repression. We use this phenomenon to measure the concentration of glucose in honey by calibrating the color of E. coli medium using android-based mobile phone. Creation of novel circuit which consists of constitutive promoter followed by either Adenylate Cyclase or IIAGlc genes, which placed downward lac-mRFP circuit, may affect the sensitivity of catabolite repression. We expect an engineered E. coli, which shows red color expression in different range of glucose concentration. By changing mRFP gene with amilCP, a blue fluorescent protein, we may obtain E. coli expressing either red or blue color when different honey added to the medium due to different glucose concentration.