Evaluating the effect of the surface morphology on the colorimetric sensitivity of poly-vinyl-pyrrolidone polydiacetylene composites

Abstract

In this paper, we report the generation of Poly-vinyl-pyrrolidone (PVP) microfibers doped with two types of polydiacetylene (PDA): 10, 12-tricosadyinoic acid (TCDA) and 10,12-pentacosadiynoic acid (PCDA). The colorimetric transition behavior of the fibrous samples upon exposure to acetone stimulus is evaluated and compared to PVP layers doped with TCDA and PCDA. The quasi-instantaneous color shift of PVP-PDA microfibers and layers is quantitatively characterized by mean of UV-visible spectrometry and the colorimetric response (CR) is calculated from the absorption spectrums. The results show that PVP can be successfully used as a low cost host matrix for the development of PDA chemo and biosensors. In addition, the chemosensors exhibit sigmoidal behavior upon exposure to different acetone solutions and samples doped with TCDA present a higher sensitivity than samples doped with PCDA due to the length of their alkyl tail. Finally, the fibrous structure significantly enhance the sensors sensitivity by 1.6 times for TCDA samples and 10 times for PCDA samples highlighting the importance of the high surface to volume ratio provided by the electrospun fibers.