A novel molecularly imprinted ratiometric fluorescent probe was fabricated by simple sol–gel polymerization for selective and sensitive assay of C-type natriuretic peptide (CNP) in biosamples. Both the nitrobenzoxadiazole (NBD) and carbon dots (CDs) were located on the surface of silica, used as the detection signal and reference signal, respectively. For the turn-on-based probe, the fluorescence intensity of NBD could be quantitatively enhanced by CNP based on the strategy of photo-induced electron transfer (PET), while the fluorescence of CDs remained unchanged. The obtained probe exhibited excellent recognition selectivity and fast kinetics to CNP templates, and also showed good stability. The linear range of CNP determination was 5–80 pg mL−1 with a low detection limit of 2.87 pg mL−1. Finally, the probe was successfully applied to determine CNP in human serum samples and attained high recoveries between 97.3 and 104% with precisions below 4.7%. The result indicates that the proposed method has promising potential for the assay of trace peptides in complex matrices. Schematic illustration for the formation and determination mechanism of the probe Schematic illustration for the formation and determination mechanism of the probe

中文翻译：

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使用具有高选择性和灵敏度的分子印迹比率荧光探针对 C 型利钠肽进行荧光开启测定

通过简单的溶胶-凝胶聚合制备了一种新型分子印迹比率荧光探针，用于生物样品中 C 型利钠肽 (CNP) 的选择性和灵敏测定。硝基苯并恶二唑 (NBD) 和碳点 (CD) 均位于二氧化硅表面，分别用作检测信号和参考信号。对于基于开启的探针，基于光诱导电子转移（PET）策略的CNP可以定量增强NBD的荧光强度，而CDs的荧光保持不变。所得探针对CNP模板表现出优异的识别选择性和快速动力学，同时也表现出良好的稳定性。CNP 测定的线性范围为 5-80 pg mL-1，检测限低为 2.87 pg mL-1。最后，该探针成功应用于人血清样品中CNP的测定，回收率高达97.3-104%，精度低于4.7%。结果表明，所提出的方法在检测复杂基质中的痕量肽方面具有广阔的应用前景。探针的形成和确定机理示意图 探针的形成和确定机理示意图