Early Screening for Cervical Squamous Cell Carcinoma and Precancerous Lesions Based on Surface-Enhanced Raman...

MicroRNAs (miRNAs) play a significant role in the development, progression, invasion and metastasis of tumours. Their serum concentrations are closely associated with the progression of tumour diseases and hold promise for cancer diagnosis. This study developed a microarray chip based on surface-enhanced Raman scattering (SERS) technology for the highly sensitive detection of cervical cancer biomarkers (miRNA103a and miRNA221). The combination of SERS technology with the microarray chip enables the simultaneous and repeatable detection of multiple samples.

An array of gold-silver nanoboxes (Au-AgNBs) was constructed via self-assembly at the oil-water interface and anchored within the wells of the microarray chip. Capture DNA (DNAmiRNA103a-Cy3 and DNAmiRNA221-Cy5) was immobilised on the surface of the Au-AgNBs array via gold-sulphur bonds to serve as the capture matrix, thereby constructing the microarray chip. When signal molecules approach the substrate, the SERS signal intensity is enhanced. When target molecules (miRNA103a and miRNA221) are present in the detection environment, they bind to the corresponding capture DNA via complementary base pairing, forming double-stranded nucleic acids. Upon the addition of a double-stranded nucleic acid-specific nuclease (DSN nuclease), the double strand is specifically cleaved, releasing the signal molecules and resulting in a decrease in the SERS signal intensity in the detection environment. The characteristics of the microarray chip, including reproducibility and sensitivity, were characterised. Microarray chips and qRT-PCR were used to detect miRNA103a and miRNA221 in the serum of 30 healthy individuals (control group), 30 patients with low-grade cervical intraepithelial neoplasia (LSIL), 30 patients with high-grade cervical intraepithelial neoplasia (HSIL), and 30 patients with cervical cancer (stage 1A).

The prepared microarray chip demonstrated good reproducibility and sensitivity. Under optimal testing conditions, the lower limits of detection for miRNA-103a and miRNA-221 on the microarray chip were 1.0934 × 10^-14 M/L and 7.5667 × 10^-13 M/L, respectively. Serum samples from healthy subjects, patients with LSIL, HSIL and cervical cancer (stage 1A) were analysed, and the results were compared with those obtained using the qRT-PCR method. The relative error between the two methods was less than 10%, and the results were statistically significant (P < 0.05).

Microarray chips provide a reliable new method for the early screening of cervical cancer. This simple and efficient microarray chip preparation method demonstrates excellent potential for application in experiments involving multiple samples and replicates. Microarray chips exhibit excellent ability to distinguish between disease states, capable of differentiating between healthy individuals, patients with LSIL, HSIL and cervical cancer.