CA 15-3-specific molecularly imprinted polymer nanoparticles-based voltammetric sensor for breast cancer monitoring.

Cancer antigen 15-3 (CA 15-3) is a critical biomarker for breast cancer, used to monitor disease severity and recurrence. Furthermore, its detection can be beneficial in post-operative treatment. Thus, biosensors that can track CA 15-3 levels in patients would provide useful data for disease monitoring. This study proposed molecularly imprinted polymer nanoparticles (nanoMIPs) specific for CA 15-3 detection; furthermore, the synthesized nanoMIPs were combined with an electrochemical sensor for breast cancer monitoring. The CA 15-3-specific nanoMIPs were generated via solid-phase synthesis. For sensor fabrication, a screen-printed carbon electrode (SPCE) was decorated with multi-walled carbon nanotubes and Au nanoparticles to improve the sensitivity. 4-aminothiophenol (4-ATP) enabled linking the synthesized CA 15-3-specific nanoMIPs to the electrode via the reaction with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). Characterizations via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and the electrochemical method suggested the successful modification of the SPCE surface. Square wave voltammetry (SWV) was used to evaluate the sensor's performance in detecting CA 15-3. The sensor exhibited a wide detection range from 1 to 100 U/mL of CA 15-3 and a limit of detection (LOD) of 0.14 U/mL. The detection range covered the reference level (30 U/mL) of CA 15-3, allowing for distinguishing between healthy people and patients. The sensor allowed for the accurate and reliable determination of CA 15-3 concentrations in serum samples after pretreatment. In addition, the proposed sensor offers advantages in terms of easy fabrication and detection, low costs, and disposability. Therefore, it could serve as an alternative device for breast cancer monitoring.