Early cancer diagnosis is paramount for enhancing treatment efficacy, extending patient survival, and improving the quality of life. We developed a highly sensitive electrochemical biosensor for the detection of target DNA (tDNA) associated with gastric cancer. This advancement integrates dual signal amplification strategies: bio-barcode amplification (BCA) and surface-initiated enzyme polymerization (SIEP), with copper nanoclusters (CuNCs) serving as signal labels. Silica nanoparticles (SiO2) were covalently linked with polythymine (poly T) and complementary DNA to create bio-barcode probes. These probes, through hybridization, were immobilized on the reduced graphene oxide and Au nanoparticle (rGO-AuNPs) modified interface and marking the first amplification of the electrical signal. Subsequently, the extended poly T prompted by SIEP bound additional CuNCs through the combination of T-Cu2+, leading to a second round of signal amplification. The biosensor demonstrated a minimum detection limit of 0.13 fmol/L over a linear response range from 1 fmol/L to 1 nmol/L. It also showcased excellent specificity, repeatability, and stability, making it a promising tool for the sensitive detection of gastric cancer biomarkers.

中文翻译：

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基于铜纳米簇的级联扩增 DNA 电化学检测结合生物条形码检测和表面引发的酶聚合


癌症早期诊断对于提高治疗效果、延长患者生存期和改善生活质量至关重要。我们开发了一种高灵敏度的电化学生物传感器，用于检测与胃癌相关的靶 DNA （tDNA）。这一进步集成了双重信号放大策略：生物条形码放大 （BCA） 和表面引发的酶聚合 （SIEP），铜纳米簇 （CuNC） 用作信号标记。二氧化硅纳米颗粒 （SiO2） 与聚胸腺嘧啶 （poly T） 和互补 DNA 共价连接，以产生生物条形码探针。这些探针通过杂交固定在还原的氧化石墨烯和 Au 纳米颗粒 （rGO-AuNPs） 修饰的界面上，标志着电信号的首次放大。随后，SIEP 引发的扩展 poly T 通过 T-Cu2+ 的组合结合其他 CuNC，导致第二轮信号放大。生物传感器在 1 fmol/L 至 1 nmol/L 的线性响应范围内显示最小检测限为 0.13 fmol/L。它还表现出优异的特异性、可重复性和稳定性，使其成为灵敏检测胃癌生物标志物的有前途的工具。