Compact biosensor system for the quantification of hydrogen peroxide in milk

Hydrogen peroxide is usually added to products to delay the development of microorganisms mainly in milk, hence increasing its stability over time, however the side effects can become devastating to human health. A technique is presented consisting of detecting hydrogen peroxide as an adulterant in milk through a sensor where pretreatment of the sample is not necessary, using a single use membrane. The detection of hydrogen peroxide in fresh-raw, whole, semi-skimmed and skimmed milk was performed using a luminol chemiluminescence reaction. For hydrogen peroxide water solutions, a linear response was attained from 1.0 × 10 −4 to 9.0 × 10 −3 %w/w and an LOD (limit of detection) of 3.0 × 10 −5 %w/w was determined. An R-squared value of 0.97 and a relative standard deviation lower than 10%, were achieved. Hydrogen peroxide concentration as low as 1.0 × 10 −3 %w/w was measured for fresh-raw, skim and whole milk and for semi-skimmed milk, as low as 2.0 × 10 −3 %w/w. The methodology presented, as long as our knowledge, is original, rapid, ecological and inexpensive. In regard of the sensitivity obtained, the methodology has great possibility to be applied in the detection of hydrogen peroxide in several areas. It is envisaged monitoring of food quality, agriculture systems and environment pollution. • New chemiluminescence sensor for quantification of concentration of H 2 O 2 in water with detection limit of 3.0 × 10 −5 %w/w. • Detection and measurement of H 2 O 2 as an adulterant in milk using a hydroxyethylcellulose-based membrane. • Real-time quantitative assessment of H 2 O 2 in milk, at concentrations as low as 1.0 × 10 −3 %w/w.