Application of electrospun poly (vinyl alcohol)/ chitosan nanofibers decorated with silver nanoparticles for thiourea determination

Recently, electrospinning has become a flexible and economical method for extracting extremely fine polymer fibers from melting polymer fibers or viscous polymer solutions, with diameters varying from a few nanometers to microns. The unique characteristics of electrospun nanofibrous membranes such as large specific surface area, small inter fibrous pore size, excellent interconnectivity and controlled fiber diameter make them useful in various fields. In the present work, a simple colorimetric sensor has been successfully designed by in-situ formation of silver nanoparticles (AgNPs) onto electrospun poly (vinyl alcohol)/chitosan (PVA/CS) nanofibers for determination of trace thiourea. The sensor probe was created by interaction of silver ions with free amino groups in the chitosan framework of PVA/CS nanofibers surface, and subsequently reduced by ascorbic acid, which causes decorated AgNPs onto the surface of nanofibers. The presence of thiourea influenced the intensity of plasmon resonance absorbance of AgNPs, which was utilized as a colorimetric probe for fast and ecofriendly detection of thiourea. The nanofibers were characterized by FE-SEM, EDX and FT-IR analysis. Under the optimal conditions, the linear analytical range of ۰.۰۲۴-۰.۲۴۰ μg mL-۱ and a detection limit of ۰.۰۰۹ μg mL-۱ were achieved for thiourea. The relative standard deviation for seven replicate measurements of ۰.۰۸ and ۰.۱۶ μg mL-۱ of thiourea was ۵.۹ and ۴.۲%, respectively. The suggested method was successfully applied for the determination of thiourea in real samples.

کلیدواژه ها:

Chitosan ، Poly (vinyl alcohol) ، Silver nanoparticles ، Thiourea ، Electrospun nanofibers