Thermal biosensor for detecting nonylphenol in the environment

The main goal of the research was the development of thermal immune biosensor for highly sensitive and specific determination of nonylphenol (NPh), based on measuring the heat released as a result of the interaction between hapten and specific antibodies. As it was shown previously, in case of SPR based immune biosensor a number of algorithms of analysis was realized, including "competitive" (with the sensitivity on the level of about 7-10 ng/ml), "direct" (10 ng/ml) ways, and the so called algorithm "to saturation" (about 2-5 ng/ml). The time of analysis by immune SPR biosensor is about 10 min (on the previously prepared transducer surface, including immobilization of sensitive structures). The developed thermal biosensor provides direct detection of NPh with the sensitivity of about 1 microg/ml and the overall time of analysis of about 20-30 min. In spite of a lower sensitivity of the thermal biosensor, it is less sensitive to admixtures in real samples and simpler in use than the biosensor based on SPR and, consequently, the thermal biosensor is more applicable in the field conditions.