In this study, we report the synthesis and application of polyethylenimine, ethylenediamine branched-functionalized carbon quantum dots (CQDs.BPEI) for protein sensing. These carbon-based nanoparticles were found to act as a protein-responsive platform. On this basis, the CQDs.BPEI system was able to detect eight different proteins (four metallic and four non-metallic), even using concentrations in the range of 5–40 nM, depending on the analyte protein. The fluorescence titrations performed at 298 and 310 K displayed fluorescence quenching, which can be explained through a collisional mechanism. It was also possible to conclude that the fluorescence quench comes from the amino acid residues on the surface of the proteins. To further check the potential of the system, we developed a “nose”-based methodology to identify proteins. Using materials, such as copper acetate and ethylenediaminetetraacetic acid, our chemical “nose” approach was able to discriminate 40 nM proteins in phosphate buffered saline (pH 7.4). In this case, the identification accuracy of the random unknown set was 83%. Overall, the results evidence the potential of CQDs.BPEI as a protein-responsive probe to detect and identify proteins.

在这项研究中，我们报告了聚乙烯亚胺，乙二胺支化官能化碳量子点（CQDs.BPEI）的合成和应用，用于蛋白质传感。发现这些基于碳的纳米颗粒充当蛋白质响应平台。在此基础上，CQDs.BPEI系统甚至可以使用5–40 nM的浓度（取决于分析物蛋白质）检测八种不同的蛋白质（四种金属和四种非金属）。在298和310 K下进行的荧光滴定显示出荧光猝灭，这可以通过碰撞机理来解释。也有可能得出结论，荧光猝灭来自蛋白质表面的氨基酸残基。为了进一步检查该系统的潜力，我们开发了一种基于“鼻子”的方法来鉴定蛋白质。使用材料 例如乙酸铜和乙二胺四乙酸，我们的化学“鼻”方法能够区分磷酸盐缓冲液（pH 7.4）中的40 nM蛋白。在这种情况下，随机未知集的识别准确度为83％。总的来说，这些结果证明了CQDs.BPEI作为蛋白质响应探针检测和鉴定蛋白质的潜力。