Development of Aloe Vera-Green Banana Saba-Curcumin Composite Film for Colorimetric Detection of Ferrum (II)

Abstract

This study was performed to develop and characterize a bio-film composed of Aloe vera (Aloe barbadensis), green banana Saba (Musa acuminata x balbisiana), and curcumin for the detection of Fe2+ ions. Cross-linking interaction between banana starch-aloe vera gel and banana starch-curcumin enhanced l the sensing performance of the composite film towards divalent metal ions of Fe2+. The morphological structure of the Aloe vera-banana starch-curcumin composite revealed a smooth and compact surface without cracks and some heterogeneity when observed under Scanning Electron Microscopy (SEM). The thickness, density, color property, opacity, biodegradation, moisture content, water-solubility, water absorption, swelling degree, and water vapor permeability of bio-films were measured. The incorporation of aloe vera gel and curcumin particles onto the banana starch film has successfully improved the film properties. The formation of the curcumin-ferrum (II) complex has triggered the film to transform color from yellow to greenish-brown after interaction with Fe2+ ions that exhibit an accuracy of 101.11% within a swift reaction time. Good linearity (R2 = 0.9845) of response on colorimetric analysis was also obtained in Fe2+ ions concentration that ranges from 0 to 100 ppm, with a limit of detection and quantification found at 27.84 ppm and 92.81 ppm, respectively. In this context, the film was highly selective towards Fe2+ ions because no changes of color occur through naked eye observation when films interact with other metal ions, including Fe3+, Pb2+, Ni2+, Cd2+, and Cu2+. Thus, these findings encourage curcumin-based starch films as sensing materials to detect Fe2+ ions in the field of food and agriculture.

An Update on the Use of Natural Pigments and Pigment Nanoparticle Adducts for Metal Detection Based on Colour Response

“…A red-brown colour was also observed for Fe 3+ at pH 2 [92], although it was claimed to be selective against Ni, Cu, K, Mn, Cr, Mg, Zn, Na, Ca, Ba, Cd and Co ions, and was found to be the most sensitive for Fe 3+ [30,59,91,92]. Fe 2+ detection was also performed using a biofilm composed of mixed curcumin, banana (Musa acuminata x balbisiana) and aloe vera (Aloe barbadensis); a greenish-brown colour was observed and confirmed by UV-Vis spectroscopy, with a wavelength shift from 426 nm to 410 nm [88]. The main challenge of using curcumin as a colorimetric indicator for metal detection is its naturally pH-dependent property, which may lead to false positives, especially in alkaline conditions, although some studies reported that the methods are selective for certain metals.…”

“…Metal detection was then developed using synthesised curcumin-based materials, such as nanofibers, nanoparticle films, cryogels, biofilms, and zein membranes, as summarised in Table 2. Fabricated modification is one of the alternatives to improve the bioavailability, solubility, and stability of curcumin; it also tends to improve the chelating ability, sensitivity, and selectivity of curcumin-based sensors [88]. In terms of portability, nanofiber-type materials are highly portable as they are ready to use in fabricated form, easy to handle, simple and stable, and suitable for rapid colorimetric detection with visual observation [89].…”

Natural and Engineered Nanomaterials for the Identification of Heavy Metal Ions—A Review

“…The presence of Pb 2+ caused the color to change from orange to red, with detection limits of 9 µM and 0.9 µM through observation with the naked eye and image processing, respectively. Vonnie et al [ 42 ] investigated the activity of a biofilm containing Aloe vera, green banana Saba, and curcumin in detecting Fe 2+ ions. Using colorimetric analysis, good linearity (R 2 = 0.9845) was found for Fe 2+ ions concentrations of 0 to 100 ppm, with limits of detection and quantification found to be 27.84 ppm and 92.81 ppm, respectively.…”

Poly(pro-curcumin) Materials Exhibit Dual Release Rates and Prolonged Antioxidant Activity as Thin Films and Self-Assembled Particles

“…35 The diketone group in curcumin can also be functionalized by interacting with polymers bearing boronic acids 36,37 or complexation with metal ions. 38,39 Because the carrier polymers in drug-polymer conjugates are usually pharmaceutically inactive and only serve as a scaffold, drug loading is limited. 40,41 Higher drug loading can be achieved by directly incorporating curcumin into the polymer's chemical structure, where such poly(pro-drugs) act both as the carrier matrix material and a depot of the drug itself.…”

“…Another strategy to enhance the solubility and long-term stability of curcumin is to conjugate the reactive phenol groups to the side chains of polyethylene glycol, , hyaluronic acid, − sodium alginate, or xylan . The diketone group in curcumin can also be functionalized by interacting with polymers bearing boronic acids , or complexation with metal ions. , Because the carrier polymers in drug-polymer conjugates are usually pharmaceutically inactive and only serve as a scaffold, drug loading is limited. , Higher drug loading can be achieved by directly incorporating curcumin into the polymer’s chemical structure, where such poly­(pro-drugs) act both as the carrier matrix material and a depot of the drug itself . Curcumin-containing polyacetals, , polyoxalates, polycarbonates, , polyurethane, and polyesters , have been reported, and the release of curcumin from these materials were either rapid (<30 h) or sustained (2–80 days), ,,, depending on the stability of the linker chemistry used to enchain the drug molecules.…”