Abstract:
Colon cancer remains one of the most elusive cancers to detect, as it often shows no symptoms in its early stages. Additionally, its gold-standard diagnostics carry substantial risks, while existing cancer detection studies are narrowly focused on the microscopic scale, leaving a critical gap in safe, effective, and accessible detection methods. Hence, this study aims to address these drawbacks through exploring the potential of GOQDs derived from Coffea arabica L. waste as a novel macroscopic detector of HCT166 cell lines. Baseline characterization using UV/Vis and FTIR spectroscopy revealed that GOQDs 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 GOQDs. The GOQDs' potential for detecting HCT116 cell line was distinguishable through the naked eye and were validated through fluorescence measurements, where GOQDs-HCT116 samples demonstrated 46.30% fluorescence in blue colorimetry at an 80% concentration, compared to 7.50% for healthy cells with GOQDs. Additionally, in vivo analyses using Drosophila melanogaster in three standardized tests (oral, direct-smash, and homogenization) with a fixed 1 mL GOQDs treatment corroborated the in vitro results, showing that cancer-induced flies exhibited the highest fluorescence with 55.56% gap in blue colorimetry. Cytotoxicity assessment via the MTT assay revealed that GOQDs had an IC50 value of 3.26 μg/mL and could inhibit 97-100% of cancer cells at 7.5 μg/mL. Consequently, EPR spectroscopy identified that GOQDs exhibit unpaired electrons, which generate ROS that contribute to cancer cell inhibition. The marketability of GOQDs was also evaluated, showing a production cost reduction of 37,579 times, an 82.5-fold increase in diagnostic speed, and a 12,240-fold reduction in retrieval time. This study confirms that GOQDs synthesized from Coffea arabica L. provide a novel method for detecting the HCT116 cell line, while also exhibiting cytotoxic activity.
