A highly sensitive safrole sensor based on polyvinyl acetate (PVAc) nanofiber-coated QCM

Kuwat Triyana,Ahmad Hasan As’Ari,Risa Suryana,Hutomo Suryo Wasisto,Roto Roto,Ahmad Kusumaatmaja,Doni Bowo Nugroho,Aditya Rianjanu

doi:10.1038/s41598-019-51851-0

Abstract

A novel, highly sensitive and selective safrole sensor has been developed using quartz crystal microbalance (QCM) coated with polyvinyl acetate (PVAc) nanofibers. The nanofibers were collected on the QCM sensing surface using an electrospinning method with an average diameter ranging from 612 nm to 698 nm and relatively high Q–factors (rigid coating). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the PVAc nanofiber surface morphology, confirming its high surface area and roughness, which are beneficial in improving the sensor sensitivity compared to its thin-film counterpart. The as-spun PVAc nanofiber sensor could demonstrate a safrole limit of detection (LOD) of down to 0.7 ppm with a response time of 171 s and a sensitivity of 1.866 Hz/ppm. It also showed good reproducibility, rapid response time, and excellent recovery. Moreover, cross-interference of the QCM sensor response to non-target gases was investigated, yielding very low cross-sensitivity and high selectivity of the safrole sensor. Owing to its high robustness and low fabrication cost, this proposed sensing device is expected to be a promising alternative to classical instrumental analytical methods for monitoring safrole-based drug precursors.

Highlights

Electrospinning is a simple and versatile technique that can create a micron–thick film containing sub-micron scale nanofibers
Gravimetric sensors based on quartz crystal microbalance (QCM) have been preferred to be used for vapor detection because of their high sensitivity, fast response, inexpensive production, real-time measurement capability, and simple integration with other electronic components[19,20,21,22,23,24]
The morphology of polyvinyl acetate (PVAc) thin-film produced by a spin coating process revealed a smooth surface with several pores (see Fig. 3(a))

Summary

Introduction

Electrospinning is a simple and versatile technique that can create a micron–thick film containing sub-micron scale nanofibers. The high specific surface area and porosity of electrospun nanofibers have sparked an increasing interest in their use as ultrasensitive gas sensors[9,10,11,12] They have recently been used as active sensing layers and integrated onto various gas sensor platforms including resistive[13], photoelectric[14], amperometric[15], optical[16], and acoustic wave[17,18]. Among these devices, gravimetric sensors based on quartz crystal microbalance (QCM) have been preferred to be used for vapor detection because of their high sensitivity, fast response, inexpensive production, real-time measurement capability, and simple integration with other electronic components[19,20,21,22,23,24]. To demonstrate its feasibility as a practical sensor in a real field, cross-sensitivity measurements toward other non-target gases were conducted and evaluated

Methods

Results

Conclusion