Abstract：
High interference and narrow application range are key of bottleneck of recent fluorescence analysis methods, which limit their wide application in the sensing field. Therefore, to overcome these disadvantages, a ratiometric fluorescence sensing system utilizing berberine (BER) and silver nanoclusters protected by dihydrolipoic acid (DHLA-AgNCs) was constructed for the first time in this work, to achieve determination of BER and daunorubicin (Dau). BER aqueous solution (non-planar conformation) has no fluorescence emission. When it was mixed with DHLA-AgNCs, the conformation of BER became planar, producing fluorescence emission at 515 nm besides the fluorescence emission peak of DHLA-AgNCs at 653 nm. With the increase of BER concentration added in system, the fluorescence intensity of BER (planar conformation) at 515 nm increased obviously and the fluorescence intensity of DHLA-AgNCs decreased slightly. Therefore, the dual emission fluorescence sensing system was constructed based on a fluorescence substance and non fluorescence substance, to achieve determination of BER. Meanwhile, based on the bridging effect of BER and fluorescence resonance energy transfer effect from Dau, the altering of two peaks intensity was utilized to achieve determination of Dau. Thus, this dual emission sensing system can not only be used for fluorescence analysis of BER and its analogues, but also based on the bridging effect of BER, allowing the determination of Dau and its analogues that could not be directly measured with silver nanoclusters, expanding the application range of traditional dual emission detection systems. Meanwhile, this system has strong anti-interference ability and low toxicity to the human body and less pollution to the sample and environment. This provides a new direction and universal research strategy for the construction of new fluorescence sensing systems in the future for the analysis of target substances that cannot be directly detected with conventional fluorescence analysis methods.
摘要：
高干扰和应用范围窄是目前荧光分析方法的瓶颈,限制了其在传感领域的广泛应用。因此,为了克服这些缺点，在这项工作中，首次构建了利用小檗碱（BER）和二氢硫辛酸（DHLA-AgNCs）保护的银纳米簇的比率荧光传感系统，实现BER和柔红霉素(Dau)的测定。BER水溶液(非平面构象)没有荧光发射。当它与DHLA-AgNCs混合时，BER的构象变成了平面，除了DHLA-AgNCs在653nm处的荧光发射峰之外,还在515nm处产生荧光发射。随着系统中BER浓度的增加,515nm处BER（平面构象）的荧光强度明显增加，DHLA-AgNCs的荧光强度略有下降。因此,构建了基于荧光物质和非荧光物质的双发射荧光传感系统,实现BER的测定。同时,基于BER的桥接效应和Dau的荧光共振能量转移效应，利用两个峰强度的改变来实现Dau的测定。因此，这种双发射传感系统不仅可以用于BER及其类似物的荧光分析，但也基于误码率的桥接效应，允许测定不能用银纳米团簇直接测量的Dau及其类似物，拓展了传统双排放检测系统的应用范围。同时,该系统抗干扰能力强，对人体毒性低，对样品和环境污染少。这为今后新型荧光传感系统的构建提供了新的方向和普适性的研究策略,用于常规荧光分析方法无法直接检测的目标物质的分析。
