Cancer biomarker profiling using nanozyme containing iron oxide loaded with gold particles

Nanozymes are nanomaterials with intrinsic magnetism and superparamagnetic properties. In the presence of an external magnet, nanozyme particles aggregate and redisperse without a foreign attraction. We evaluated the performances of nanozyme by changing the biosensing platforms and substituting other biological variants for a complete cancer assay detection. We investigated the expression of morphological variants in the transmission of signals using an electrochemical method. The signal responses, including signal enhancement with the nanozyme (Au-Fe₂O₃), showed a wide capturing range (greater than 80%, from 10² to 10⁵ cells ml^-1 in phosphate-buffered saline buffer, pH 7.4). The platform showed a fast response time within a dynamic range of 10-10⁵ cells ml^-1 for the investigated T47D cancer cell line. We also obtained higher responses for anti-HER2 (human epidermal receptor 2)/streptavidin interface as the biosensing electrode in the presence of T47D cancer cells. The positive assay produced a sixfold increase in current output compared to the negative target or negative biological variant. We calculated the limit of detection at 0.4 U ml^-1, and of quantitation at 4 U ml^-1 (units per millilitre). However, blood volume amounts in clinical settings may constrain diagnosis and increase detection limit value significantly.