Au@Fe 3 O 4 Nanoparticle-Based Colorimetric Aptasensor for Noninvasive Screening of Colorectal Cancer via Detection of Parvimonas micra

作者：Shanshan Feng, Peiyi Zhang, Hui Chen, Bo Zhou, Ying� Qin, Tingting Fan, Qinsheng Sun, Yan Chen, Yuyang Jiang · 发表于：ACS Sensors · 年份：2025 · DOI：10.1021/acssensors.4c02885 · 被引用次数：6 · 研究领域：Advanced Nanomaterials in Catalysis、Biosensors and Analytical Detection、Advanced biosensing and bioanalysis techniques

Colorectal cancer (CRC) is a common malignancy requiring early screening to improve patient outcomes. Current screening methods such as colonoscopy and fecal occult blood tests have several limitations including high cost, poor specificity, invasiveness, and inconvenience. Recent research has identified specific bacterial communities associated with CRC, notably Parvimonas micra ( P. micra ), which serves as a biomarker for early screening and diagnosis owing to its accumulation in the malignant tissues and feces of CRC patients. Herein, we employed the whole-bacterium systematic evolution of ligands by the exponential enrichment (SELEX) method to isolate high-affinity aptamers against P. micra using 17 selection cycles. These aptamers were subsequently bound to Au@Fe 3 O 4 nanoparticles, and the interaction of P. micra and aptamers inhibited the peroxidase-like activity of Au@Fe 3 O 4 nanoparticles, thereby blocking the 3,3′,5,5′-tetramethylbenzidine (TMB) chromogenic reaction and resulting in a measurable reduction in absorbance. This colorimetric detection strategy demonstrated a linear response across a range of 10 0 –10 8 CFU/mL for P. micra with a limit of detection of 11 CFU/mL. Using a colorimetric aptasensor, we assessed the abundance of P. micra in clinical fecal samples and found significantly higher levels in the feces of CRC patients as compared to that of healthy individuals, which was consistent with the quantitative polymerase chain reaction results. This stud...