Engineered fluorescent carbon dots for selective cellular bioeffects: a comparative study of cancer and normal cells

Abstract

Cancer remains one of the most critical global health challenges, with early detection being essential for effective treatment and improved survival rates. However, conventional diagnostic tools often fail to detect cancer at early stages due to limitations such as low sensitivity, high cost, and dependence on large tumour presence. Commercial dyes used for imaging are frequently hindered by poor water solubility, toxicity, instability, and high expense. In recent years, CDs have emerged as promising fluorescent probes due to their nanoscale size, tenable surface properties, strong fluorescence, and excellent biocompatibility. make them applicable to various biological applications such as bioimaging, drug delivery, and tissue engineering. In this study, CDs were synthesized using citric acid and ascorbic acid as carbon sources via a reflux method at 130 °C for 12 hours in a water-ethanol medium. The resulting CDs exhibited high water solubility, strong photostability, and low toxicity. Notably, they effectively distinguished cancerous cells from normal cells. And showing higher uptake in cancer cells due to increased membrane permeability and metabolic activity. Higher uptake means more accumulation within cells that leads to an increment in fluorescence intensity, based on the fluorescent intensity distinguishing the cancer cells and normal cells. These findings highlight the potential of CDs as cost-effective, biocompatible imaging agents for cancer diagnosis and cellular studies.