LoC-SERS detection platform based on targeted signal anchoring mechanism, high-sensitivity detection of protein biomarkers in precancerous lesions of gastric cancer

Abstract

In this study, a novel lab-on-a-chip surface-enhanced Raman scattering (LoC-SERS) analysis platform was developed based on chip laboratory for monitoring precancerous lesions of GC. The platform integrated graphene-like Au nano-hexagonal arrays (Au NHAs) as a high-efficiency plasma substrate with the highly integrated microarray chip as an ideal system for sensitive recognition and rapid quantification of matrix metalloproteinase-9 (MMP-9) and interleukin-6 (IL-6) based on the targeted signal anchoring mechanism. Au NHAs were surface modified to form a double stranded structure with aptamer chains and single stranded DNA1 (ssDNA1), Au nanobipyramid with Ag shell (Au NBP@Ag) surface modified single stranded DNA2 (ssDNA2) and Raman signaling molecules. When the target is present, the aptamer specifically captures the target protein and detaches from the Au NHAs surface, exposing ssDNA1 and ssDNA2 to pair and bind. This resulted in the Au NBP@Ag probe carrying the signaling molecule anchoring to the surface of Au NHAs, thereby enhancing the SERS signal. The platform demonstrated excellent detection efficiency and could complete detection tasks within 20 min. The platform can detect MMP-9 and IL-6 at levels down to the pg/mL order of magnitude, demonstrating excellent detection sensitivity. In addition, the platform has the capability of simultaneous dual-target detection, demonstrating good clinical applicability and accuracy when testing real serum samples. Overall, this platform provides an efficient solution for early diagnosis and progression monitoring of precancerous lesions of GC, further providing a scientific basis for clinical decision-making and intervention.