A love-mode surface acoustic wave aptasensor with dummy fingers based on monolayer MoS/Au NPs nanocomposites for alpha-fetoprotein detection.

The detection of cancer markers still has shortages of low sensitivity, time-consuming operation, the use of unstable and expensive antibodies. In this work, a novel Love-mode surface acoustic wave (LSAW) aptasensor with dummy fingers based on the monolayer molybdenum disulfide/gold nanoparticles (monolayer MoS/Au NPs) was developed for the highly sensitive and rapid determination of alpha-fetoprotein (AFP) in serum. Interdigital electrodes (IDTs) with dummy fingers were designed and applied to improve the acoustic characteristic of the LSAW aptasensor. The less energy dissipation and wave-front distortion of the LSAW aptasensor were confirmed by COMSOL simulation and test results. The newly-developed sensing film monolayer MoS/Au NPs/Apt/6-mercaptohexanol (MCH) was applied for the specific detection of AFP and significantly improved the sensitivity of the LSAW aptasensor. The excellent performance of the LSAW aptasensor allowed the sensitive and rapid detection of AFP in serum in the range of 0.01 ⁓ 100 ng/mL with a low detection limit of 4.79 pg/mL. Additionally, the proposed LSAW aptasensor exhibited excellent selectivity, long-term stability, and reproducibility, and could be used to detect other cancer biomarkers.