As is well documented, prostate cancer (PCa) being the second most prevalent cancer in men worldwide, emphasizing the importance of early diagnosis for prognosis. However, conventional prostate-specific antigen (PSA) testing lacks sufficient diagnostic efficiency due to its relatively low sensitivity and limited detection range. Mounting evidence suggests that matrix metalloproteinase 9 (MMP-9) expression increases with the aggressive behavior of PCa, highlighting the significance of detecting the serum level of MMP-9 in patients. Developing a non-immune rapid, portable MMP-9 detection strategy and investigating its representativeness of PCa serum markers hold considerable implications. Herein, our study developed a simple, homogeneous dual fluorescence and smartphone-assisted red-green-blue (RGB) visualization peptide sensor of MMP-9, utilizing cadmium telluride quantum dots (CdTe QDs) and calcein as signal reporters. The essence of our approach revolves around the proteolytic ability of MMP-9, exploiting the selective recognition of molecule-Cu complexes with different molecular weights by CdTe QDs and calcein. Under optimized conditions, the limits of detection (LODs) for MMP-9 were 0.5 pg/mL and 6 pg/mL using fluorescence and RGB values readouts, respectively. Indeed, this strategy exhibited robust specificity and anti-interference ability. MMP-9 was quantified in 42 clinical serum samples dual-fluorescence analysis, with 12 samples being visually identified with a smartphone. According to receiver operating characteristic curve (ROC) analysis, its sensitivity and specificity were 90 % and 100 %, respectively, with an area under curve (AUC) value of 0.903. Of note, the results of the aforementioned analysis were highly consistent with the serum level of PSA, clinical color Doppler flow imaging (CDFI), and histopathological results. Therefore, this simple, rapid, homogeneous fluorescence and visualization strategy can reliably measure MMP-9 levels and exhibit promising potential in point-of-care testing (POCT) applications for PCa patients.

中文翻译：

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荧光探针信号传导的生物分子调节：血清中均质快速便携式蛋白酶传感


众所周知，前列腺癌 (PCa) 是全球男性中第二常见的癌症，这强调了早期诊断对预后的重要性。然而，传统的前列腺特异性抗原（PSA）检测由于其相对较低的灵敏度和有限的检测范围而缺乏足够的诊断效率。越来越多的证据表明，基质金属蛋白酶 9 (MMP-9) 的表达随着 PCa 的侵袭行为而增加，凸显了检测患者血清 MMP-9 水平的重要性。开发一种非免疫快速、便携式 MMP-9 检测策略并研究其 PCa 血清标志物的代表性具有相当大的意义。在此，我们的研究开发了一种简单、均匀的双荧光和智能手机辅助的 MMP-9 红绿蓝 (RGB) 可视化肽传感器，利用碲化镉量子点 (CdTe QD) 和钙黄绿素作为信号报告剂。我们的方法的本质是围绕 MMP-9 的蛋白水解能力，利用 CdTe QD 和钙黄绿素对不同分子量的分子-Cu 复合物的选择性识别。在优化条件下，使用荧光和 RGB 值读数时，MMP-9 的检测限 (LOD) 分别为 0.5 pg/mL 和 6 pg/mL。事实上，该策略表现出强大的特异性和抗干扰能力。通过双荧光分析对 42 个临床血清样本中的 MMP-9 进行了定量，其中 12 个样本通过智能手机进行了视觉识别。根据受试者工作特征曲线（ROC）分析，其敏感性和特异性分别为90%和100%，曲线下面积（AUC）值为0.903。 值得注意的是，上述分析结果与血清PSA水平、临床彩色多普勒血流成像（CDFI）和组织病理学结果高度一致。因此，这种简单、快速、均匀的荧光和可视化策略可以可靠地测量 MMP-9 水平，并在 PCa 患者的即时检测 (POCT) 应用中展现出广阔的潜力。