Electrochemical Aptasensor for PD-L1 Detection in Non-Small Cell Lung Cancer with In Silico Approach and DNA Strand Displacement Reaction

Abstract

Programmed death-ligand 1 (PD-L1) is the protein that overexpresses in many solid tumors, such as non-small cell lung cancer (NSCLC). In NSCLC treatments, the expression of PD-L1 can predict the responsiveness of patients to PD-1/PD-L1 blockade. Conventionally, PD-L1 is detected through immunohistochemistry, which exhibits human error limitations and various PD-L1-positive cut-off values, complicating the data interpretation and increasing the risk of misclassification among patients.Here, we developed the electrochemical aptasensor to detect the circulating form of PD-L1 in the serum of the NSCLC patients. This aptasensor combined the in silico molecular docking of aptamer to design the reporter probe used with the DNA strand displacement reaction, where one of the strands in prehybridized double-strand DNA binds to the target, causing the displacement of the other hybridized strand. Therefore, the aptamer prehybridized with the gold nanoparticle-labeled reporter probe will recognize the PD-L1 and displace the reporter probe, allowing electrochemical detection. The electrochemical signal will correlate with the quantity of PD-L1 in samples, providing a reliable approach for PD-L1 detection.