Food Glucometer

A normal glucometer is a medical device often used by diabetics to determine the approximate concentration of glucose in the blood. The testing is done by a painful lancet prick in the finger to draw blood, the blood is then placed on a testing strip and then placed in the tester to receive the results. A normal person’s glucose concentration with no pancreas abnormalities is in the range of 80-180 mg/dL. A person with a compromised pancreas has a higher glucose concentration from 200 mg/dL to 600 mg/dL, which most glucometers max out at. Carbonated beverages such as Coke have around 3 g/fl oz, a much greater concentration than an ordinary glucose meter can viably analyze.

In this project, a food glucometer was created which takes the sugar content of various food items, aggregates with a mixture of Benedict’s solution, and gives the user a reading of the amount of sugar in the food by interpreting the resultant color change using a RGB reader module.

Benedict’s solution is a chemical solution that changes color in the presence of glucose. It is initially a clear blue solution which is a mixture of copper sulfate, sodium carbonate, and sodium citrate. This solution, in the presence of simple sugars such as glucose when heated, creates Cuprite nanoparticles, and thus changes color from a range of its initial blue color to a bright red hue as more glucose is added. A color sensor is used to convert the color to glucose concentration. It is calibrated in the wavelength range of 450nm to 650nm. Since the color change is created from the creation of cuprite nanoparticles, there is in theory no limit to how high the glucometer can test. However, sugar does not completely dissolve after it reaches its saturation point in a solution.

The advantages of the food glucometer created here are its low cost and its capability of measurements of high glucose concentration. The other advantage is that it measures glucose concentration based on the food consumed rather than that in the blood content. This means that there are no painful finger pricks and the user can get a measurement of sugar content before consumption, meaning no surprise spikes in blood sugar.