Pineapple-Leaf-Derived, Copper-PAN-Modified Regenerated Cellulose Sheet Used as a Hydrogen Sulfide Indicator

Abstract

Regenerated cellulose (RC) produced from waste pineapple leaves was used to develop a colorimetric sensor as a Cu-PAN sheet (RCS). Microcrystalline cellulose derived from dried pineapple leaves was combined with Cu-PAN, dissolved in NaOH and urea, and made into an RC sheet using Na₂SO₄ as a coagulant. The RCS was used as an H₂S indicator at various H₂S concentrations (0–50 ppm) and temperatures (5–25 °C). The RCS color changed from purple to New York pink when exposed to H₂S. A colorimeter method was used to develop prediction curves with values of R² > 0.95 for H₂S concentrations at 5–25 °C. The physicochemical properties of fresh and spent RCS were characterized using various techniques (Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray spectroscopy, and thermogravimetric analysis). In addition, when stored at 5 and 25 °C for 90 days, the RCS had outstanding stability. The developed RCS could be applied to food packaging as an intelligent indicator of meat spoilage.