Akademik Veri Yönetim Sistemi
MICROCHEMICAL JOURNAL, 2025 (SCI-Expanded)
Single nucleotide polymorphisms (SNPs) refer to variations at a single nucleotide position within the DNA sequence. A subset of SNPs may function as biomarkers for the early identification of specific cancer types. Colorimetric assays utilizing the aggregation of gold nanoparticles (AuNPs) for SNP detection offer significant advantages, including speed, cost-effectiveness, practicality, and high sensitivity. Peptide nucleic acid (PNA), a DNA analogue composed of peptide-like repetitive 2-aminoethyl-glycine units, exhibits a stronger binding affinity to DNA sequences compared to traditional DNA counterparts. This study presents the development of a rapid, label-free colorimetric assay based on PNA/DNA hybridization, utilizing unmodified AuNPs to detect the E545K mutation in the PIK3CA gene. The assay operates in solution, eliminating the need for immobilization, and effectively differentiates complementary DNA from both single-base mismatches and non-complementary DNA at a concentration of 20 nM, with a 0.02 DNA/PNA ratio as the detection limit. The colorimetric alterations caused by PNA, that are observed at different DNA/PNA ratios when complementary DNA is present, generated a linear coefficient of determination (R2) of 0.9268 for the standard curve. This straightforward test, which can be conducted at room temperature and requires only a spectrophotometer, offers a rapid and costefficient method for mutation detection, particularly suitable for resource-constrained environments.