Enhanced detection of HER2 using a TiVC MXenes/gold nanocomposite amplified analytical biosensor for precise cancer biomarker monitoring

Recently, aptamers have been widely used in the detection and measurement of cancer biomarkers. This issue has had a significant impact on the process of diagnosing all types of cancers. This research work explores the development and application of layer-by-layer modified electrochemical apta-sensor for the precise monitoring of HER2, a crucial biomarker associated with breast cancer. The surface of the screen-printed carbon electrode was modified with gold nanoparticle (Au-NP) and TiVC MXene catalyst plus Pb²⁺ loaded aptamer (SPCE/TiVC-MXene/Au NPs/Pb²⁺-aptamer), which showed a high selectivity and affinity towards HER2 and offered a sensitive detection platform. The MXene nano-layer was synthesized and characterized by XPS, MAP, EDS, AFM, BET, and TEM methods and used as a substrate to improve electrochemical conductivity and loading of biological recognition element. The square-wave anodic stripping voltammetry (SWASV) method was used as a highly sensitive platform in HER2 detection. The difference of stripping signals of the Pb²⁺ from the SPCE/TiVC-MXene/Au NPs/Pb²⁺-aptamer before and after incubation in HER2 solution was selected as analytical response to achieve a reliable and quantitative analysis for HER2 concentrations. The effective factors in monitoring of HER2 such as concentration of Pb²⁺, incubation time, and buffer type were optimized and results showed that 5 mM of Pb²⁺ and 90-min incubation time in Tris–HCl created best condition in fabrication of biosensor. The results demonstrate a linear dynamic range of 1.0–1200 pg/mL for monitoring of HER2 with limit of detection of 50 fg/mL. A good affinity of fabricated apta-sensor to HER2 in the presence some other biomarkers such as PR, ER, and CEA confirmed the selectivity of the fabricated biosensor towards HER2 detection.