In the present work, we integrated a prepared bio-chip with Tc-99m labeling to improve the immunoassay for cancer biomarker protein detection. Efficient binding of a Tc-99m isotope-labeled secondary antibody to the biomarker protein pre-anchored to the bio-chip was followed by detection of g rays from Tc-99m decay via a Gamma Well Counter. We show that alpha-fetoprotein (AFP), a biomarker of liver cancer, can be detected down to 10(-18) M concentration in a buffer solution with good reproducibility. This ultra-high sensitivity is attributed to the aggregation of the Tc-99m isotope-labeled secondary antibody which greatly amplifies the g rays emitted per AFP binding event. The tendency of the isotope-labeled secondary antibody to aggregate was indicated by dynamic light scattering studies on a rhenium/secondary antibody conjugate, a stable structural analogue of the Tc-99m conjugate. The successful zeptomolar-range detection of cancer biomarkers opens new avenues for early disease diagnoses via integrating bio-chips with isotope-labeling techniques.
Ma L,Tang BC,Yang WJ,et al. Integration of a bio-chip technique with technetium-99m labeling provides zeptomolar sensitivity in liver cancer biomarker detection[J]. ANALYTICAL METHODS,2015,7(4):1622-1626.
马磊.,汤博崇.,杨文江.,刘宇.,赵宇亮.,...&Li, M.(2015).Integration of a bio-chip technique with technetium-99m labeling provides zeptomolar sensitivity in liver cancer biomarker detection.ANALYTICAL METHODS,7(4),1622-1626.
马磊,et al."Integration of a bio-chip technique with technetium-99m labeling provides zeptomolar sensitivity in liver cancer biomarker detection".ANALYTICAL METHODS 7.4(2015):1622-1626.