**4. Applications**

#### **4.1. Bioapplications**

There are unlimited applications of reinforced polymer microstructures. One of the most recent application is DNA sensing based on reinforced polymer microstructuring. A conducting polymer containing nanofibrous structure can be very sensitive even to small perturbations at the interface, thanks to its high electrical conductivity and electron transfer capabilities when the interface is covered by its film. Biocompatible conducting polymers can be variably modified for immobilization of probe DNA via covalent linking or electrostatic interactions. The conductivity of the conducting polymer electrochemically deposited on the electrode surface can be modulated by changing the pH of the medium, the electrochemical potential, and/or the electrolyte. Because of these characteristics and other advantages, conducting polymers could be utilized extensively for the construction of biosensors including DNA sensors which, to the best of our knowledge, is reported for the first time.

Noble metals are known to create strong chemical bonds with compounds terminating with a thiol (-SH) group. In order to achieve immobilization of nucleic acids on solid substrates, researchers have developed techniques by which DNA molecules can be linked to a thiol group. In this case, the thiolated terminal of molecules is chemisorbed on the substrate, while the DNA portion of the molecules are standing parallel to each other and away from the substrate. Since they are formed quickly, resulting in a well-defined and reproducible surface, and are stable under normal laboratory conditions, gold electrodes are fabricated using femtosecond laser material processing or other techniques [41].

#### **4.2. Energy applications**

materials and hence, it is not surprising in these polymers. However, these trace impurities do not affect the quality of our ferromagnetic composites. Figure 8 (c) shows the magnetic measurements of the nanofibers reinforced polymers which has a coercive field HC of approximately 260 Oe at room temperature. This large coercivity suggests that oxide nano‐

It can be seen that the magnetization of the generated nanofibers reinforced polymer increases compared to pure polymer. This increase in magnetization is expected below the superpara‐ magnetic- ferromagnetic transition temperature, which is above 300K for the magnetic nanofibers of 20 nm average size due to reduced thermal activation energy. Nanoparticle interactions, which depend on the iron concentration in the polymer matrix, strongly influence the remnant magnetization. Since agglomeration of nanoparticles into nanofibers is observed in all our polymer nanofibers reinforced polymer samples, interactions are expected to play a significant role in the magnetic response. These interactions lead to a non- linear increase in MR as the concentration of iron is increased. The magnetic interactions are generally expected to be dipolar in nature, although in strongly coupled clusters, exchange interactions are also

**Figure 8.** Room temperature M-H curves (a) Magnetic nanofiberous structures, (b) Ormocer, and (c) magnetic nano‐

There are unlimited applications of reinforced polymer microstructures. One of the most recent application is DNA sensing based on reinforced polymer microstructuring. A conducting polymer containing nanofibrous structure can be very sensitive even to small perturbations at the interface, thanks to its high electrical conductivity and electron transfer capabilities when the interface is covered by its film. Biocompatible conducting polymers can be variably

fibrers are present on the microstructure.

possible.

178 Advances in Nanofibers

fibers reinforced polymer.

**4. Applications**

**4.1. Bioapplications**

Reinfoced polymer microstructuring can be utilized in neomerous application. Researchers prepared dye-sensitized solar cells using micro/nanofibers reinforced polymer Ti02 porous films [42]. This result in cells with enhanced light collection. They applied a technique which opens an alternative way for manufacturing solar cells on an industrial scale. Ti02 micro/nanocomposite structured electrodes for quasi-solid-state dye-sensitized solar cells [43]. These revolutionary nano-structured ultra thin film solar PV products will provide affordable clean renewable energy for everyone. Another unique technology has been developed that absorbs and converts more sunlight throughout the day by utilizing special kind of nanofibers reinforced polymers. This result in a dramatic increase in total power output. Each nanofiber increases the total PV surface area by an incredible 6-12 times over current other thin film products on the market today. Figure 9 shows luminescent solar concentrators (LSCs) comprising CdSe core/multishell quantum dots (QDs) developed by Bomm et al [44].

**Figure 9.** (a) Photograph of a P (LMA-co-EGDM) plate containing CdSe core/multishell QDs (illuminated by a UV-lamp) illustrating the concentrator effect and (b) TEM image of a QD-LSC/P (LMA-co-EGDM) nanofibers reinforced polymer showing single QDs and a few small QD aggregates [44].
