A plasmonic mesoporous gold-based SERS-microfluidic platform for the detection of infectious diseases†

Infectious diseases, particularly those caused by pathogens and parasites, present significant global health challenges. Despite advancements in medicine, these diseases continue to result in high rates of illness, loss of function, and mortality. The continuous COVID-19 pandemic, stemming from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlights the critical necessity for early detection strategies to improve patient outcomes. We present a novel microfluidics platform for the simultaneous detection of proteins (antigens) crucial for SARS-CoV-2 identification: S1, RBD, and NCD. By combining microfluidics with surface-enhanced Raman scattering (SERS), the platform enables highly sensitive and multiplexed detection of viral proteins. Furthermore, it employs an engineered mesoporous gold nanoparticle (mAuNP)-based SERS nanotags to achieve a highly sensitive readout. Demonstrating excellent analytical performance, our platform simultaneously detects three antigens, achieving detection levels as low as 14 pg mL⁻¹, with an RSD of <5.0% (n = 3). Compared to existing approaches, our platform offers critical improvements for SARS-CoV-2-like infectious disease analysis. It provides a multiplex detection system alongside controls, a simple experimental setup, and a single-device-based complete assay platform. The mAuNP-based SERS nanotags eliminate the need for enzymatic amplification, while the portable SERS readout facilitates an on-site detection without sophisticated instrumentation or laboratory requirements.