Highly sensitive and simultaneous detection of ctDNAs related to non-small cell lung cancer in serum using a catalytic hairpin assembly strategy in a SERS microfluidic chip

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Vol. 1; no. 32; pp. 6194 - 626
• Main Authors: Cao, Xiaowei, Mao, Yu, Gu, Yuexing, Ge, Shengjie, Lu, Wenbo, Gu, Yingyan, Li, Zhiyue
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 17.08.2022
• Subjects: Assembly; Biomarkers; Biopsy; blood serum; Cancer screening; Detection limits; DNA; DNA probes; humans; Lung cancer; lung neoplasms; Medical screening; Microfluidics; Non-small cell lung carcinoma; organ-on-a-chip; Raman spectra; Reaction products; Small cell lung carcinoma; Substrates; Tumors
• ISSN: 2050-750X; 2050-7518; 2050-7518
• DOI: 10.1039/d2tb01024k

Circulating tumor DNA (ctDNA) is an ideal biomarker for cancer diagnosis based on liquid biopsy, so there is an urgent need for developing an efficient, rapid, and ultrasensitive detection method to meet clinical needs. In this paper, a novel surface-enhanced Raman scattering (SERS) microfluidic chip combined with a catalytic hairpin assembly (CHA) was proposed to detect two non-small cell lung cancer (NSCLC)-related ctDNA (TP53 and PIK3CA-Q546K) simultaneously. The chip consists of six channels for parallel detection. In the reaction region, the CHA reaction between HP 1 of the SERS probe and HP 2 of the capture substrate was triggered by ctDNAs to form HP 1 -HP 2 duplexes. As the reaction proceeds, more and more SERS probes are captured on the substrate. The gathered reaction products continuously form a lot of hot spots, which greatly enhance the SERS signal. This reaction was completed within 5 minutes. Through this method, the detection limits of TP53 and PIK3CA-Q546K in human serum were as low as 2.26 aM and 2.34 aM, respectively. The microfluidic chip also exhibited high specificity, reproducibility and stability. The clinical feasibility of the SERS microfluidic chip was verified by analyzing the serum samples of healthy subjects and NSCLC patients. The reliability of the experimental results was verified by the qRT-PCR test. The constructed SERS-based analytical micro-platform has great potential in dynamic monitoring of cancer staging and could be used as a clinical tool for early cancer screening. A catalytic hairpin assembly-based SERS microfluidic chip was developed for rapid, sensitive, and simultaneous detection of two NSCLC-related ctDNAs.