Simultaneous detection of multiple trace cancer associated serum miRNA biomarkers is considered as a feasible method for early cancer screening and diagnosis. In the present work, an ultrasensitive SERS sensor was prepared based on an Ag nanorod array SERS substrate by assembling special hairpin-shaped molecular beacons (MBs) for the detection of multiple lung cancer-related miRNA biomarkers. The portable SERS sensor exhibits excellent performance for the qualitative and quantitative detection of miRNAs, with advantages of ultra-sensitivity, good specificity, uniformity, reproducibility and stability, as well as remarkable reusability. By monitoring the SERS signal quenching of the MBs in the presence of target miRNA biomarkers, three lung cancer related-miRNAs (miRNA-21, miRNA-486, and miRNA-375) in buffer and human serum were simultaneously assayed using the SERS sensor array, and the limits of detection of the three miRNAs in human serum are 393 aM, 176 aM, and 144 aM, respectively. The reliable results demonstrate that the proposed SERS sensor array can be a promising candidate with great potential for the screening and clinical diagnosis of cancer in the early stage.

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The physicochemical properties of noble metal nanocrystals depend strongly on their size and shape, and it is becoming clear that the design and facile synthesis of particular nanostructures with tailored shape and size is especially important. Herein a novel class of hydrangea flower-like hierarchical gold nanostructures with tunable surface topographies and optical properties are prepared for the first time by a facile, one-pot, seedless synthesis using ascorbic acid (AA) to reduce hydrogen tetrachloroaurate (HAuCl4) in the presence of (1-hexadecyl)trimethylammonium chloride (CTAC). The morphologies of the synthesized gold nanoflowers are controlled and fine-tuned by varying the synthetic conditions such as the concentration of reagents and the growth temperature. Due to their unique hierarchical three-dimensional (3D) structures with rich hot spots, these gold nanoflowers exhibit an efficient performance in single-particle surface-enhanced Raman scattering (SERS). The work stands out as an interesting approach for anisotropic particle synthesis and morphological control, and the proposed novel, hierarchical gold nanoflowers have a number of exciting potential applications in SERS-based sensors.

A highly sensitive and specific SERS-based combination assay of lung cancer associated serum markers is reported, and the LODs of CEA and NSE in human serum specimens are 1.48 pg mL−1 and 2.04 pg mL−1, respectively.