Title : Non-toxic one-pot synthesis of carbon quantum dots from pomelo (Citrus maxima) peel Waste as a polychromatic fluorescent robe for acute and astute detection of Cu²⁺, K⁺, Ca²⁺, Mg²⁺, & Fe²⁺
Abstract:
Heavy Metal water contamination is a critical environmental concern. Thus, it has detrimental effects on human health such as cancer, multiple-organ failure and neurodegenerative diseases. Hence, this study explored the potential of the non-toxic synthesis of carbon quantum dots ( C Q D s ) through microwave-assisted technique from Pomelo (Citrus maxima) peels. It also explored the capabilities of CQD as a sensitive and selective detection of Cu²⁺, K+, Ca²⁺, Mg²⁺, and Fe²⁺. The methods involved collection of the fruit peeling samples, green synthesis of CQD through microwave-assisted technique, and testing its polychromatic fluorescent properties among different heavy metal effluents. Data were collected using the neulog logger light sensor and neulog logger colorimeter. Baseline characterization using UV/Vis and FTIR spectroscopy revealed that CQDs exhibit optimal excitation within the UV-B spectrum and contain hydroxyl and carboxyl groups. Further analysis using XRD, TEM, EDX, and FESEM confirmed the successful synthesis of CQDs. To further analyze the fluorescence yield of CQD, it was tested using Wavelength Dispersive X-ray Fluorescence (WDXRF) conducted at Chulalongkorn University in Bangkok, Thailand. The results showed that the CQD sample is sensitive and selective to the detection of Potassium ion (K+ ) i n Green, Copper ion ( Cu²⁺) in Red, Calcium ion (Ca²⁺) in color Blue and UV Light, Magnesium ion (Mg²⁺) in UV Light alone and Iron ion (Fe2+) in color Orange. Furthermore, Calcium ion (Ca²⁺) and Iron ion (Fe2+) can still be distinguished at the very least concentration at 0.5%. This is evident through their distinctive polychromatic fluorescence properties, with these heavy metals showing the most pronounced responses compared to others tested.
