Current Trends in Polymer Based Sensors

Abstract

This review illustrates various types of polymer and nanocomposite polymeric based sensors used in a wide variety of devices. Moreover, it provides an overview of the trends and challenges in sensor research. As fundamental components of new devices, polymers play an important role in sensing applications. Indeed, polymers offer many advantages for sensor technologies: their manufacturing methods are pretty simple, they are relatively low-cost materials, and they can be functionalized and placed on different substrates. Polymers can participate in sensing mechanisms or act as supports for the sensing units. Another good quality of polymer-based materials is that their chemical structure can be modified to enhance their reactivity, biocompatibility, resistance to degradation, and flexibility.

Shaping Macromolecules for Sensing Applications—From Polymer Hydrogels to Foldamers

“…For instance, Wei et al developed a microfluidic device that incorporates an aptamer-based hydrogel for the detection of cocaine [ 56 , 73 ]. Hydrogels, thanks to the aforementioned characteristics, such as the ability to retain molecules of water and swell in media, softness, and ease of derivatization, have gained interest as transducer materials in sensing and biosensing technologies [ 7 , 9 , 12 ].…”

“…They are built into a three-electrode electrochemical cell, consisting of a working electrode (WE), a counter or an auxiliary electrode, and a reference electrode. Different materials are used as WEs, e.g., glassy carbon electrodes, carbon paste electrodes, pencil graphite electrodes, indium tin oxide electrodes, pyrolytic graphite electrodes, gold or platinum electrodes, and carbon or gold screen-printed electrodes [ 12 , 79 ]. The WE presents the electroconductive materials which are responsible for biorecognition event with the targeted species, causing the change of the electrochemical signal, recorded as impedance, current, or voltage.…”

“…Polymers are versatile materials that represent a broad range of properties and stimuli-responsiveness, thus very attractive for sensors construction [ 12 , 13 , 14 , 15 , 16 ]. These materials can be adapted to specific tasks through their synthesis or modification [ 17 , 18 , 19 ] and may be used as solid membranes, gels, nanoparticles, or thin films [ 20 , 21 , 22 , 23 ].…”

Fabrication of an All-Solid-State Ammonium Paper Electrode Using a Graphite-Polyvinyl Butyral Transducer Layer

“…Graphite is an inexpensive and abundant material, with adequately low resistivity for the aforementioned purpose, and can be manufactured into a wide variety of forms, making it a popular choice as an electrode material [28]. The next step in the development of the ammonia sensing platform consisted of applying the ion-selective membrane mixture in volumes of 30 µL (electrode 1) and 50 µL (electrode 2) directly onto the surface of the graphite electrode [9]. Therefore, after drying at air conditions for 24 h, two different ammonium-selective membrane coated graphite electrodes were prepared and tested in the analyte solutions (Figure 2).…”

“…Historically, the first proposed concept of sensors without internal solutioncoated wire electrodes-was extremely simple but, mainly because of the potential instability, not reliable [8]. To overcome this problem, solid transducer layers consisting of redox-polymers [9] or nanostructured materials [10] were introduced into the domain of SC-ISE sensor design. The transducer layer is usually built over the electrode material or over a noble metal contact.…”