A novel biosensor based on well-aligned manganese-doped ZnO nanorods for detecting lung cancer antigen

Cytokeratin 19 (CK19) fragment is a well-known biomarker for lung cancer, and early and precise detection is crucial for efficient therapeutic care. In this work, we report a new biosensor that uses well-aligned manganese (Mn)-doped zinc oxide (ZnO) nanorods as the sensing element to detect CK19 with high sensitivity and specificity. ZnO nanorods doped with Mn ions on a glassy carbon electrode (Mn-doped ZnO NRs/GCE) were modified by the electroception method, and then anti-CK19 and bovine serum albumin (BSA) were immobilized on modified electrodes (BSA/anti-CK19/Mn-doped ZnO/GCE), respectively. Cyclic voltammetry (CV) and Fourier-transform infrared spectroscopy (FTIRS) verified that anti-CK19 and BSA were successfully immobilized on the Mn-doped ZnO nanorods. In order to determine CK19, the tests employing CV and differential pulse voltammetry (DPV) methodologies showed that BSA/anti-CK19/Mn-doped ZnO/GCE showed excellent reproducibility, repeatability, sensitivity, selectivity, and stability. The BSA/anti-CK19/Mn-doped ZnO/GCE showed a linear response over a concentration range of 0.5 ng/mL to 1000 µg/mL. The results indicated that the sensitivity and limit of detection were 0.094 ng/mL and 6.37697 μA/mgL-1, respectively. The biosensor that has been presented has the potential to significantly improve the early detection of lung cancer, which would eventually improve patient outcomes and survival rates.