KCS

For the fast and accurate detection of prostate cancer markers, a novel surface-enhanced Raman scattering (SERS)-based microfluidic chip was developed for the simultaneous detection of free prostate-specific antigen (f-PSA) and total PSA (t-PSA) markers. In this study, we described a fully automatic droplet-based microfluidic platform for the rapid and sensitive detection of f-PSA and t-PSA. The device was composed of three compartments: mixing and reaction, auto separation, and SERS detections. Sandwich immunoassays for f-PSA and t-PSA biomarkers were performed using sequential microdroplets to avoid tedious washing steps. Raman signals of sequential droplets including supernatant solutions were measured for the quantitative analysis of the PSA markers. The results showed a good linear response for both PSA markers in the range from 0.05 to 100 ng mL−1. The limits of detection were estimated to be below 0.1 ng mL−1 for both the f-PSA and t-PSA. This low LOD level demonstrates that the detection limit of our SERS-based microfluidic immunoassay is much lower than the clinical threshold. Therefore, our proposed method is a very promising clinical tool for the PSA-based screening test of prostate cancer. References 1. R. Gao, Z. Cheng, X. Wang, L. Yu, Z. Guo, G. Zhao, J. Choo, Biosens. Bioelectron., 119, 126 (2018). 2. Z. Cheng, N. Choi, R. Wang, S. Lee, K.C. Moon, S.-Y. Yoon, L. Chen, J. Choo, ACS Nano, 11, 4926 (2017). Keywords: SERS, microdroplet device, PSA, multiplex immunoassays