Thermal based sensor as a platform for biosensors:detecting small molecules with Molecularly Imprinted Polymers (MIPs)

Abstract

In this work a biosensor for small molecules has been developed by functionalizing a thermal based sensor with molecularly imprinted polymers(MIPs). This work proves the functionality of the thermal based sensor and of the molecularly imprinted polymers. Recently the transducing technique based on the thermal resistivity of the solid-liquid interface has been miniaturised by utilizing the transient plane source(TPS) technique. Although the TPS technique has been confirmed to be able to characterize fluids, no functional layer has yet been tested. Three functional layers have been added to the sensor to develop a working biosensor. The first layer is a layer of polyimide(Kapton). It provides electrical insulation from the fluid that contains the analyte. Moreover, polyimide has acceptable thermal properties and will not leave the molecules undetected. The second layer is polyvinylchloride(PVC). It is spincoated on top of the polyimide which produces a layer of several nanometres. This layer too will not pose a threat to the detection. The last layer is the MIP layer. MIPs have a diameter of 20-40 µm. They are stamped onto the PVC and fixated into it by elevating the temperature of the sensor to 120°C. The sensor has been tested by applying solutions with and without the analyte. The results prove that the thermal sensor can be functionalized to detect small molecules. This means that the thermal sensor can be used as a platform for all different kinds of biosensors.