摘要 |
A sensor for detecting a presence of bacteria in a perishable food includes a pH sensitive solution of bromothymol blue and methyl red mixed with an alkaline resulting in a pH value and a generally green color changing to a generally orange color responsive to exposure to a concentration of carbon dioxide. The solution is packaged in a gas permeable container using a TPX (PMP) thin film that allows an effective diffusion of carbon dioxide through the container. The pH level drops when acidic carbon dioxide comes into contact with the solution resulting from a formation of carbonic acid, making the solution an indicator of carbon dioxide concentration, and thus an indication of bacterial growth.
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