Abstract：
BACKGROUND: Cobalt, an essential trace element, is vital for maintaining human nervous system function, aiding in DNA synthesis, and contributing to red blood cell production. It is helpful for disease diagnosis and treatment plan evaluation by precisely monitoring its concentration changes in the human body. Despite extensive efforts made, due to its ultra-low concentration, the current limit of detection (LOD) as reported is still inadequate and cannot be satisfied with the precise clinical applications. Therefore, it is crucial to develop novel label-free sensors with high sensitivity and excellent selectivity for detecting trace amounts of Co2+.
RESULTS: Here, an ultrasensitive optical fiber SPR sensor was designed and fabricated for label-free detection of Co2+ with ultra-low concentration. It is achieved by modifying the carboxyl-functionalized CQDs on the AuNPs/Au film-coated hetero-core fiber, which can specifically capture the Co2+, leading to changes in the fiber\'s surface refractive index (RI) and subsequent SPR wavelength shifts in the transmission spectrum. Both the Au film and AuNPs on the fiber are modified with CQDs, leveraging their large surface area to enhance the number of active sites and probes. The sensor exhibits an ultra-high sensitivity of approximately 6.67 × 1019 nm/M, and the LOD is obtained as low as 5.36 × 10-20 M which is several orders of magnitude lower compared to other conventional methods. It is also experimentally demonstrated that the sensor possesses excellent specificity, stability, and repeatability, which may be adapted for detecting real clinical samples.
CONCLUSIONS: The CQDs-functionalized optical fiber SPR sensor exhibits substantial potential for precisely detecting Co2+ of trace amounts, which is especially vital for scarce clinical samples. Additionally, the sensing platform with sample sensor fabrication and measurement configuration introduces a novel, highly sensitive approach to biochemical analysis, particularly adapting for applications involving the detection of trace targets, which could also be employed to detect various biochemical targets by facile modification of CQDs with specific groups or biomolecules.
RESULTS: Here, an ultrasensitive optical fiber SPR sensor was designed and fabricated for label-free detection of Co2+ with ultra-low concentration. It is achieved by modifying the carboxyl-functionalized CQDs on the AuNPs/Au film-coated hetero-core fiber, which can specifically capture the Co2+, leading to changes in the fiber\'s surface refractive index (RI) and subsequent SPR wavelength shifts in the transmission spectrum. Both the Au film and AuNPs on the fiber are modified with CQDs, leveraging their large surface area to enhance the number of active sites and probes. The sensor exhibits an ultra-high sensitivity of approximately 6.67 × 1019 nm/M, and the LOD is obtained as low as 5.36 × 10-20 M which is several orders of magnitude lower compared to other conventional methods. It is also experimentally demonstrated that the sensor possesses excellent specificity, stability, and repeatability, which may be adapted for detecting real clinical samples.
CONCLUSIONS: The CQDs-functionalized optical fiber SPR sensor exhibits substantial potential for precisely detecting Co2+ of trace amounts, which is especially vital for scarce clinical samples. Additionally, the sensing platform with sample sensor fabrication and measurement configuration introduces a novel, highly sensitive approach to biochemical analysis, particularly adapting for applications involving the detection of trace targets, which could also be employed to detect various biochemical targets by facile modification of CQDs with specific groups or biomolecules.
摘要：
背景：钴，一种必需的微量元素，对维持人类神经系统功能至关重要，帮助DNA合成，并有助于红细胞的产生。通过精确监测其在人体内的浓度变化，有助于疾病诊断和治疗方案评估。尽管作出了广泛的努力，由于其超低的浓度，目前报告的检测限(LOD)仍然不足,不能满足精确的临床应用.因此,开发具有高灵敏度和优异选择性的新型无标记传感器对于检测痕量Co2+至关重要。
结果：这里，设计并制作了一种超灵敏光纤SPR传感器，用于超低浓度Co2+的无标记检测。它是通过修饰AuNP/Au薄膜涂层的杂芯纤维上的羧基官能化CQDs来实现的，它可以专门捕获Co2+，导致光纤表面折射率（RI）的变化以及随后的SPR波长在透射光谱中的偏移。光纤上的Au膜和AuNP都用CQDs改性，利用它们的大表面积来增加活性位点和探针的数量。该传感器具有约6.67×1019nm/M的超高灵敏度，LOD低至5.36×10-20M，与其他常规方法相比要低几个数量级。实验证明该传感器具有优异的特异性,稳定性,和可重复性，其可以适于检测真实的临床样本。
结论：CQDs功能化光纤SPR传感器显示出精确检测痕量Co2+的巨大潜力，这对稀缺的临床样本尤其重要。此外,具有样品传感器制造和测量配置的传感平台引入了一种新颖的，高度敏感的生化分析方法，特别适用于涉及痕量目标检测的应用，通过用特定基团或生物分子轻松修饰CQDs，也可用于检测各种生化靶标。
结果：这里，设计并制作了一种超灵敏光纤SPR传感器，用于超低浓度Co2+的无标记检测。它是通过修饰AuNP/Au薄膜涂层的杂芯纤维上的羧基官能化CQDs来实现的，它可以专门捕获Co2+，导致光纤表面折射率（RI）的变化以及随后的SPR波长在透射光谱中的偏移。光纤上的Au膜和AuNP都用CQDs改性，利用它们的大表面积来增加活性位点和探针的数量。该传感器具有约6.67×1019nm/M的超高灵敏度，LOD低至5.36×10-20M，与其他常规方法相比要低几个数量级。实验证明该传感器具有优异的特异性,稳定性,和可重复性，其可以适于检测真实的临床样本。
结论：CQDs功能化光纤SPR传感器显示出精确检测痕量Co2+的巨大潜力，这对稀缺的临床样本尤其重要。此外,具有样品传感器制造和测量配置的传感平台引入了一种新颖的，高度敏感的生化分析方法，特别适用于涉及痕量目标检测的应用，通过用特定基团或生物分子轻松修饰CQDs，也可用于检测各种生化靶标。
