Sulfur-doped g-C3N4/Polycaprolactone nanofibers based smart sensor for 8-hydroxy-2′-deoxyguanosine biomarker monitoring

The compound 8-hydroxy-2′-deoxyguanosine (8-OHdG) is a key byproduct of oxidative DNA damage and is widely recognized as an important biomarker for assessing DNA oxidation levels. This study presents a label-free, low-cost, smart sensor that can improve evaluation, tracking, and survival rates by allowing for an early assessment of cancer. Herein, we fabricate sulfur-doped graphitic carbon nitride (S-gC₃N₄) embedded in polycaprolactone (PCL) for highly efficient monitoring of 8-OHdG. The S-gC₃N₄ offers functional groups such as sulfur and nitrogen that facilitate strong binding interactions with 8-OHdG. Comprehensive techniques are utilized to investigate the S-gC₃N₄/PCL nanocomposite. Interestingly, the S-gC₃N₄/PCL nanocomposite demonstrates strong electrochemical responses to the oxidation of 8-OHdG, with a low detection limit across a wide dynamic concentration range (1 nM–50 μM). Additionally, it exhibits good durability, selectivity, reusability, and repeatability. The developed sensor has the potential to quantify 8-OHdG levels in individuals and can be used to evaluate oxidative DNA damage and risk factor for cancer. Furthermore, the S-gC₃N₄/PCL-based sensor is successfully tested to determine 8-OHdG levels in human serum samples.