Comparison of three immunosensor methods (surface plasmon resonance, screen-printed and classical amperometric immunosensors) for immunoglobulin G determination in human serum and animal or powdered milks

Within the framework of research carried out by our team aimed at developing new immunological methods to determine proteins such as immunoglobulins G in different biological matrixes, for instance, serum and milk, tests were performed on several immunosensors based on different transducer types, i.e. amperometric (classical or screen-printed) electrodes for hydrogen peroxide. Lastly the feasibility of constructing immunosensors based on surface plasmon resonance (SPR) was investigated. “Competitive” immunological procedures were used in the first two cases. Conversely, the surface plasmon resonance transduction technique allowed a “direct” measurement. Applications were performed on human serum, powdered milks for babies and particularly on several animal milks, in the case of buffalo milk seeking a routine control method to identify possible inflammatory affections in the animals.

► We developed new immunological methods for IgG determination in serum and milk.
► We compared three different immunosensors (amperometric, screen-printed and SPR).
► The Kaff (affinity constant) value was evaluated for all the methods.
► High IgG value may be symptom of mastitis thus of interest in veterinary practice.
► Amperometric and SPR methods allowed to obtain information on the cattle's health.