Research Information System
Microchemical Journal, vol.218, 2025 (SCI-Expanded, Scopus)
Circulating tumor DNA (ctDNA) is a vital biomarker for early cancer diagnosis, prognosis, and treatment monitoring, despite challenges posed by its low concentrations. This study presents a highly sensitive and selective method for detecting ctDNA by integrating a magnetic bead-assisted biosensor system with Ligase Chain Reaction (LCR), capable of recognizing single-nucleotide polymorphisms (SNPs). Our approach involved amplifying ctDNA using LCR, producing ferrocene- and biotin-labeled single-strand products. These products were then separated explicitly from non-amplified DNA using streptavidin magnetic beads, thereby enhancing sensitivity. The isolated, amplified ctDNA was subsequently quantified using anodic differential pulse voltammetry (DPV), which leveraged the specific binding of the labeled DNA. Under optimized conditions, the developed electrochemical biosensor demonstrated sensitive analytical performance for target ctDNA, exhibiting a linear range of 100 pM to 500 nM and a detection limit of 100 pM, along with reasonable specificity and stability. Remarkably, the system successfully analyzed SNP mutations of single-strand ctDNA in commercial human serum samples, even at low concentrations, significantly enhancing the technique's clinical applicability for ctDNA detection. Furthermore, this study employed fluorescence methods to enhance sensitivity and quantification, allowing for real-time monitoring of amplification kinetics. This fluorescent approach achieved lower ctDNA detection limits than conventional gel electrophoresis, a critical advantage for early cancer detection and SNP-based mutation identification. The electrochemical analysis further enhanced the sensitivity of ctDNA detection, enabling the detection of ultra-low concentrations in complex samples and providing precise measurements vital for monitoring treatment and disease progression. Its compatibility with miniaturization also supports the development of portable diagnostics. In summary, this research establishes a robust and highly sensitive ctDNA detection platform by synergistically combining gel electrophoresis, fluorescence, and electrochemical analysis. This integrated approach holds significant promise for advancing early cancer diagnosis, facilitating personalized treatment strategies, and ultimately improving patient outcomes.