analysis of curcuma longa and chitosan&#45;dyed fabrics for textile authentication

Use of Chitosan to Enhance Photoluminescence of Curcumin for Textile Authentication

Counterfeiting is considered a scourge in widespread industries across the globe. The rapid surge of counterfeit products in the market causes economic havoc, which impedes the livelihood of the primary inventor1,2,3,4,5,6. This was brought to the fore in 20207&#160;on the ongoing concern of emerging counterfeit products as evidenced by the increasing trend of publications consisting of the keyword anticounterfeiting or counterfeiting in their titles. A significant increase can be observed in counterfeit-related publications since last reported in 2019, suggesting that considerable efforts are being made to combat the production and distribution of fraudulent goods. On the other hand, it can also be quite alarming, given that it signifies the progression of the counterfeiting industry, which is expected to persist if not addressed effectively. The textile industry is not insulated from this problem, as the presence of counterfeit textile products has severely impacted the livelihood of genuine sellers, manufacturers and weavers, among others3,8. For instance, the textile industry in West Africa was long considered one of the leading export markets in the world. However, it was reported9&#160;that approximately 85% of the market share is held by smuggled textiles that infringe upon West African textile trademarks. The effects of counterfeiting have also been reported in other continents like Asia, America, and Europe, indicating that this crisis has reached an uncontrollable level and poses a significant threat to the already struggling textile industry2,3,4,10,11,12.
With the rapid advancements of science, technology, and innovation, researchers took upon the role of developing functional materials for the purpose of anti-counterfeiting applications. The use of covert technology is one of the most common and effective approaches to counteract the production of fraudulent goods. It involves utilizing photoluminescent materials as security dyes that exhibit a specific light emission when irradiated by different wavelengths13,14. However, some photoluminescent dyes available in the market may impose toxicity at high concentrations, thereby posing threats to human health and the environment15,16.
Turmeric (Curcuma longa) is an essential plant used in myriad applications such as paints, flavoring agents, medicine, cosmetics, and fabric dyes17. Present in the rhizomes are naturally occurring phenolic chemical compounds called curcuminoids. These curcuminoids include curcumin, demethoxycurcumin, and bisdemethoxycurcumin, among which curcumin is the main constituent responsible for the vibrant yellow to orange coloration and the properties of turmeric18. Curcumin, otherwise known as 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione19,20&#160;with an empirical formula of C21H20O6, has attracted a significant amount of attention in the biomedical and pharmaceutical fields due to its antiseptic, anti-inflammatory, anti-bacterial, and antioxidant properties17,18,21,22,23. Interestingly, curcumin also possesses spectral and photochemical characteristics. Particularly noteworthy is its intense photoluminescent properties when subjected to ultraviolet (UV) excitations which have been explored only by a few studies19,24,25. Given these characteristics, in tandem with its hydrophobic nature and non-toxic properties, curcumin emerges as an ideal colorant for authentication markings.
The extraction of curcumin from turmeric was first reported in the early 1800s. Over the past centuries, numerous extraction methodologies and techniques have been devised and improved to achieve higher yield26,27,28,29,30,31,32,33. Conventional solvent extraction is a widely used approach as it employs organic solvents such as ethanol, methanol, acetone, and hexane among others, to isolate curcumin from turmeric34,35. This method has evolved through modifications, coupled with more advanced techniques such as microwave-assisted extraction (MAE)18,36,37, Soxhlet extraction38,39, enzyme-assisted extraction (EAE)39,40, and ultrasonic extraction36, among others to increase the yield. Generally, the solvent extraction method has been applied for natural dye extraction due to its versatility, low energy requirement, and cost-effectiveness making it ideal for scalable industries such as textiles.
Curcumin has been integrated as natural dyes for textiles due to its distinct yellow hue. However, the poor adsorption of natural dyes unto textile fibers pose as a challenge that hinders its commercial viability41. Mordants, such as metals, polysaccharides, and other organic compounds, serve as common binders to strengthen the affinity of natural dyes unto the fabric. Chitosan, a polysaccharide derived from crustaceans, has been widely utilized as an alternative mordanting agent due to its abundance in nature, biocompatibility, and wash durability42. This study reports a facile and straight forward approach in preparing curcumin-based authentication marking. Crude curcumin extracts were obtained via sonication-assisted solvent extraction method. The photoluminescent properties of the extracted curcumin were comprehensively investigated on textile substrates and further enhanced with the introduction of chitosan as a mordanting agent. This demonstrates the significant potential as a naturally derived photoluminescent dye for authentication applications.

Author Spotlight: Eco-friendly Photoluminescent Textile Authentication with Curcumin

Enhanced Photoluminescence of Curcuma longa Extracts via Chitosan-Mediated Energy Transfer for Textile Authentication Applications

Several curcumin researches focus on medical and cosmetic applications. Very few have delved into its photo luminescent properties. In this study, we demonstrate a facile, cost-effective, and eco-friendly approach to enhance the photoluminescent emission of curcumin dyes, geared towards the development of covert markings for textile application.Current developments revolve around the preparation of diverse luminescent materials, such as inorganic quantum dots, carbon dots, perovskites, and synthetic organic dyes. Recent technological advances in the development of photoluminescent materials usually centralize along its industrial applications, such as LEDs. What's interesting is that these same photoluminescent materials from organic pigments to inorganic phosphorus and quantum dots are also feasible precursors for anti-counterfeiting applications when given the proper experimental design.The primary challenge in our experiment is ensuring the quality of the result we collected. We've optimized the experiment procedures to not only maintain data accuracy, but also to do so efficiently, enabling simple replications for fellow researchers interested in textiles and photoluminescence. To bind curcumin to textiles, traditional metallic mordants like iron, aluminum, and copper are used.However, metals in post-dying waste water effluence may impose environmental risk. This study utilizes chitosan, a byproduct from crabs and shrimps as alternative mordant for securing curcumin into the fabric, providing excellent color fastness properties.

Analysis of Curcuma longa and Chitosan&#45;Dyed Fabrics for Textile Authentication

To begin, warm up a fluorescent spectrophotometer for 15 to 30 minutes before measurement. Then click on measure, and set the integration time to 0.1 seconds, increments to one nanometer, slit width to one nanometers, and the signal formula to S1-CR1-C. Next, use a Pasteur pipette to carefully transfer 3.5 milliliters of a diluted Curcuma longa extract into a quartz cuvette.Measure the emission spectra with a 365 nanometer excitation source, and set the emission range from 380 nanometers to 625 nanometers. Measure the excitation spectrum of the sample with the wavelength of highest emission. Set the lower limit for the excitation range at 330 nanometers, and the upper limit set to the monitored emission wavelength minus 15 nanometers.Remeasure the emission spectrum of the sample with the highest excitation wavelength. Set the emission range starting at the excitation wavelength plus 15 nanometers up to 625 nanometers. Next, set the excitation range fixed between 330 and 435 nanometers, and the emission between 450 and 650 nanometers for all dilutions of Curcuma longa extract.Then clean the cuvette with ethanol, and measure the emissions of the remaining dilutions. To measure the emission excitation matrix of Chitosan, set the slit width to one nanometer and the integration time to 0.1 seconds, the emission ranges from 300 to 370 nanometers, and the excitation range from 385 to 450 nanometers. Then transfer the Chitosan solution to a washed cuvette, and place it in the spectrophotometer to measure its emission excitation matrix.Place a multi-tester fabric over the ATR crystal of the FTIR instrument. Then measure the IR transmittance of the fabric. To perform fluorescence analysis of the Chitosan-dyed fabric, place the fabric in the sample holder of the instrument.Fix the fabric position in the middle of the window with glass slides. Now set the integration time to 0.1 seconds, increments to one nanometer, slit width to 0.6 nanometers, and signal formula to S1C-R1C. Then set the emission range between 380 to 635 nanometers, and measure the fluorescence at 365 nanometers.Use the wavelength of highest excitation as determined by the photoluminescence analysis to measure the emission spectrum of the sample. Add 15 nanometers to the excitation wavelength, and set it as the lower limit for the emission range. Set the upper limit to 625 nanometers.Lastly, measure the emission spectra of one to 50 diluted Chitosan-finished Curcuma longa dyed fabrics at 365 nanometers. To perform morphological analysis of fabrics, first mount a handheld UV source of 365 nanometers on an iron stand. Point it towards a stereo microscope.Next, place the fabric on the stage, and open the white light source. Set the zoom to the lowest magnification to locate the target imaging area. Increase the magnification to four times, and refine the image focus with the fine adjustment knob.With the built-in imaging software, insert a scale bar and capture the image. To ensure uniform imaging, set the exposure compensation to 100, the exposure time to 100 milliseconds, and the gain to 20. Then adjust the hue values of red to 27, green to 32, and blue to 23.Lastly, adjust the sharpness to 75, de-noise to 35, saturation to 50, gamma to six, and contrast to 50. Switch on the ultraviolet lamp after turning off the white light source. Now capture the image with the same imaging parameters for all fabrics.UV analysis of the multi-test fabrics showed the successful deposition of the Curcumanoid solution at different concentrations. The photoluminescent emission spectra of Curcumanoid Chitosan-dyed fabrics showed enhanced optical properties.

Research

JoVE Journal

Chemistry

Dyes for security markings play a pivotal role in safeguarding the integrity of products across various fields, such as textiles, pharmaceuticals, food, ...