## 3 Results and Discussion
### Detection Performance as a Function of Poly(MMA-co-MAA) Polymer Coating Composition
Therefore, tuning the pore size, distribution and hydrophobicity of the bioreceptor surface highly influences the performance of the platforms in the assay. PMMA-coated PHBV fibers resulted in the greatest level of detection among all the coated samples. The next in line was coated fiber with Comp. (7:3) which has generated OD values comparable to that of PMMA-coated surfaces. Statistical analysis presented in Figure 6a shows an overall higher performances of the developed platforms in comparison to the conventional ELISA. In particular, from the presented results it can be observed that the coated PHBV fibers with PMMA and Comp. (7:3) offered significant detection sensitivity in comparison to the rest of the coating polymer compositions and the conventional assay (Figure 6a). Considering the major forces that influence the analyte-surface attraction (discussed in Section 3.2), the experimental results in Figure 6 indicate that the predominant force is hydrophobic interaction. However, relatively high OD intensities recorded for poly(MMA-co-MAA) coatings with moderate concentrations of -COOH groups (Comp. (9:1) and (7:3); Figure 6) could be related to H-binding between coatings and Ab molecules. In summary, the results presented here do not only justify this novel and highly effective analytical method for early detection of DENV but they also provide the insight into physical protein-surface, nano-scale interactions, an important aspect for future development of sensitive biosensor platforms. In addition, electrospinning technique could be optimized to produce sub-micron polymer fibers [49], which could increase the level of sensitivity of fibrous platform. Although there are several different techniques for regeneration of the analytical platforms such as treatment with strong oxidizer, acid/base components and/or concentrated salts [50; 51], reusability of the developed platforms is not debated. Since i-ELISA can be fabricated through an inexpensive and straightforward method of molding, the device can be considered as a disposable analytical platform. Therefore, it seems highly possible that i-ELISA could pave the way to the future of the electrospun fiber mat-assisted analytical well plates [50]. The fact that our novel design can be applicable for integration of several different types of paper and/or fiber products into the assay endorses such a platform as a fairly unique development. One of the most important aspects in development of novel bio-sensing platforms is the shelf life of the bioreceptor surfaces. In that perspective, stability of the surface functionalities is highly important. Conventionally modified bioreceptor surfaces often lose their activities after a specific period of time due to the aging effect or reorientation phenomenon. Generated functional groups on the surface tend to reorganize themselves in order to occupy lower levels of energy, thereby resulting in deactivation of the modified surfaces. In the present case, available surface functionalities were formed through free-radical polymerization reaction. For that reason, the surface functional groups (-COOH) are an inherent part of the chemical structure and are not expected to rearrange with time [37]. Additionally, polymer-coated electrospun PHBV fibers have shown great stability throughout the time-consuming and tedious sandwich ELISA, which involves a number of steps with several incubations. In our previous attempt at fabrication of electrospun fiber mat-based platforms, we used PHB electrospun fibers as the supporting material for dip coating [24]. The same strategy was applied for fabrication of coated fiber mats by using PHBV as the supporting material in this study. The reason for this alteration was due to the specific characteristics of the PHBV material itself. PHBV was found to possess a level of robustness in the time-consuming and laborious sandwich ELISA experiments. Additionally, PHBV is more electronegative than PHB due to the presence of oxygen atoms in its chemical structure.