Polymers For Sensor Applications Research Articles

Construction and Properties of Ripples on Polymers for Sensor Applications

Surface modification of polystyrene and polyethylene naphthalate by a KrF pulse excimer UV laser under the angles of incidence of the laser beam in the range of 0 to 60° with a step of 7.5° was studied in this paper. The influence of the angle of incidence on the period of the resulting surface structures and the modified refractive index of the substrates was determined with all the other parameters of the laser radiation held constant. All data was acquired on the basis of surface analysis. Atomic force microscopy was used to study the morphological changes in the laser treated samples and to determine the period of the ripple-like surface structures, from which the modified refractive index was subsequently calculated. Selected samples were metallized with gold with aim to determine the influence of patterned substrate on consequently formed nanolayer. These information may be useful for consequently constructed SERS system based on ripple-metal system.

Polymers in sensor applications

Because their chemical and physical properties may be tailored over a wide range of characteristics, the use of polymers is finding a permanent place in sophisticated electronic measuring devices such as sensors. During the last 5 years, polymers have gained tremendous recognition in the field of artificial sensor in the goal of mimicking natural sense organs. Better selectivity and rapid measurements have been achieved by replacing classical sensor materials with polymers involving nano technology and exploiting either the intrinsic or extrinsic functions of polymers. Semiconductors, semiconducting metal oxides, solid electrolytes, ionic membranes, and organic semiconductors have been the classical materials for sensor devices. The developing role of polymers as gas sensors, pH sensors, ion-selective sensors, humidity sensors, biosensor devices, etc., are reviewed and discussed in this paper. Both intrinsically conducting polymers and non-conducting polymers are used in sensor devices. Polymers used in sensor devices either participate in sensing mechanisms or immobilize the component responsible for sensing the analyte. Finally, current trends in sensor research and also challenges in future sensor research are discussed.

Some studies of molecularly-imprinted polymer membranes in combination with field-effect devices

Investigations of the usefulness of molecularly-imprinted polymers in sensor applications were undertaken. Thin polymer membranes containing molecular imprints against l-phenylalanine anilide were prepared and applied as sensing layer in field-effect capacitors. In this report some experimental results obtained for C-V measurements when the polymer membranes were exposed to l-phenylalanine anilide (FAA), tyrosinanilide (TA), and phenylalaninol (FA) in ethanol are presented. Despite some difficulties, it was shown that in ethanol solution the compounds FAA and TA can be measured and distinguished from FA using a imprinted polymer membrane.