Diamond-mediated immunosensing of Alpha-l-Fructosidase for diagnosing hepatocellular carcinoma: signal enhancement over conventional ELISA

Objectives Hepatocellular carcinoma (HCC) is the deadliest liver cancer, a frequent complication that originates from the liver. The common cause of HCC is the infection by Hepatitis B and C. Early diagnosis of liver cancer biomarker helps for providing a better treatment and increase the survival rate. Alpha-L-Fucosidases (AFU) is identified as a potential biomarker for HCC, in particular for detecting smaller tumours. Methods This study develops an improved enzyme linked immunosorbent assay (ELISA) on diamond nanomaterial modified polystyrene surface (PS). Diamond was modified on ELISA well through carbonyldiimidazole chemical modification and then aptamer was attached on the diamond through the biotin-streptavidin interaction. Results Diamond improves the aptamer attachment on PS well and enhances the interaction of AFU with aptamer and antibody. The limit of detection (LOD) of AFU was calculated to be 25 pg/mL based on a linear regression [y=0.0795× - 0.0857; R 2 =0.967], while the limit of quantification (LOQ) was at 85 pg/mL, which were lower than that achieved by the conventional ELISA method. Conclusions In addition, AFU spiked serum increases the absorbance with enhancing AFU, indicating the selective AFU detection and control molecules did not show the significant absorbance proves the specific AFU detection.