Biophysics and Nanoscience Centre, Faculty of Science, Università della Tuscia, Viterbo, Italy.
Int J Nanomedicine. 2011;6:2033-42. doi: 10.2147/IJN.S23845. Epub 2011 Sep 19.
One of the main challenges in biomedicine is improvement of detection sensitivity to achieve tumor marker recognition at a very low concentration when the disease is not significantly advanced. A pivotal role in cancer defense is played by the p53 tumor suppressor, therefore its detection with high sensitivity may contribute considerably to early diagnosis of cancer. In this work, we present a new analytical method based on surface-enhanced Raman spectroscopy which could significantly increase the sensitivity of traditional bioaffinity techniques. p53 molecules were anchored to gold nanoparticles by means of the bifunctional linker 4-aminothiophenol (4-ATP). The characteristic vibrational bands of the p53-4-ATP nanoparticle system were then used to identify the p53 molecules when they were captured by a recognition substrate comprising a monolayer of azurin in molecules possessing significant affinity for this tumor suppressor. The Raman signal enhancement achieved by 4-ATP-mediated crosslinking of p53 to 50 nm gold nanoparticles enabled detect of this protein at a concentration down to 5 × 10⁻¹³ M.
生物医学的主要挑战之一是提高检测灵敏度，以便在疾病尚未明显进展时，以非常低的浓度识别肿瘤标志物。p53 肿瘤抑制因子在癌症防御中起着关键作用，因此，其高灵敏度检测可能对癌症的早期诊断有很大的帮助。在这项工作中，我们提出了一种基于表面增强拉曼光谱的新分析方法，该方法可以显著提高传统生物亲和技术的灵敏度。p53 分子通过双功能连接子 4-巯基苯硼酸（4-ATP）被锚定到金纳米粒子上。然后，当 p53-4-ATP 纳米粒子系统的特征振动带被包含对这种肿瘤抑制因子具有显著亲和力的单层天青蛋白的识别底物捕获时，就可以识别出 p53 分子。通过 4-ATP 将 p53 交联到 50nm 金纳米粒子上所实现的拉曼信号增强，可以检测到浓度低至 5×10⁻¹³ M 的这种蛋白质。
