Design of a Nano-Functionalized Lab-on-Paper Optical Sensing Platform for On-Site Detection of Ascorbic Acid in Natural Fruit Juices
摘要
The optical detection of ascorbic acid was carried out using a quick and simple sensor-based approach designed by adsorbing molybdenum disulfide and silver-based polyoxometalates (MoS2-Ag-POM) on cellulose nanopaper strips. This detection method for the analysis of ascorbic acid does not require any signal-generating dye. MoS2 and Ag-POM were prepared by a hydrothermal procedure. The material and modified nanopaper surface were characterized by Fourier transform infrared (FT-IR) spectroscopy analysis, dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), UV absorption spectra, and X-ray diffraction (XRD). The MoS2-Ag-POM composite was embedded on the cellulose nano-enabled paper sensors by incorporating silica sol-gel. The modified cellulose nano-enabled paper sensors turned sky blue when exposed to ascorbic acid. The analytical quantification based on these modified cellulose nano-enabled paper sensors was performed by using a Capsure Pantone colorimetric reader. The cellulose nano-enabled paper sensor showed a strong linear correlation between light reflectance values (LRV) and the level of analyte ranging from 0.19 to 780 µM and presented a detection limit of 0.097 µM. The designed cellulose nano-enabled paper sensor was affordable, quick, and target-selective for ascorbic acid analysis in food products like fruit juice samples.
Graphical Abstract