Detection of penicillin G in milk is of interest because of the wide use of this antibiotic in livestock.
Current analytical methods used to quantify the penicillin G in milk are based on HPLC, mass spectrometry
and electrophoresis. These methodologies are time-consuming and require trained personnel. In
addition, it is not easy to envisage the development of a portable device for in situ analyses based on
these methods. We present a novel sensing approach for detecting the presence of penicillin G in milk.
The proposed method is based penicillin G conjugate labeled with red-emitting dye with properly produced
anti-penicillin G antibodies. The results obtained suggest our method could be applied directly
in milk without interference from other substances. The limit of detection of the method was
1.0 nmol/L, which is much less than the required MRL in EU regulations (12.0 nmol/L).