Gold Nanoparticles-Incorporated Electrospun Nanofibrous Membrane for Optical Biosensing Applications: An Experimental and Computational Approach.

Paper-based biosensing platforms are the leading area of research today. In this work, a platform for biosensing applications with improved detection capability has been prepared using gold nanoparticles (AuNPs) incorporated in electrospun nanofibers. The computational study results demonstrated that the addition of AuNPs brings about better stability to the polymer complex, and the energy band gap was found to be lowered for the PVA-AuNPs (E_g = 3.57 eV) compared to PVA (E_g = 8.82 eV). Based on this data, AuNPs were incorporated into the polymer matrix by immersion and dispersion techniques. Different ratios of polyvinyl alcohol (PVA) to AuNPs have been prepared, and the optical, thermal, morphological, and structural properties of the substrates were evaluated to prepare a matrix with better biosensing capabilities. Improved photoluminescence emission intensity of the order of 2.5 times higher was observed for PVA-AuNPs (7:3) nanofibers compared to bare PVA nanofibers. The improved photoluminescence emission intensity of the polymer matrix can be used as a quantitative parameter for the diagnosis of several diseases. The field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) analysis shows the successful encapsulation of AuNPs within the nanofibers with an average fiber diameter of 101 ± 21 nm and particle size of around 4.24 nm of Au NPs. The prepared PVA-AuNPs nanofibers showed stable luminescence properties (less than 10% variation) even after two months of storage at room temperature. The bioconjugation studies showed better photoluminescence emission intensity for the proposed substrate than the conventional nitrocellulose (NC) membrane. The functional performance of the modified NC membrane with electrospun nanofibers showed a three times higher response than the bare NC membrane. The present study may give new insight to use the gold-incorporated nanofibers as an additive element to the conventional NC membrane in order to bring out better bioconjugation competency with improved sensing properties. [ABSTRACT FROM AUTHOR]