Fluorescence resonance energy transfer (FRET) reporters are commonly used in the final stages of nucleic acid amplification tests to indicate the presence of nucleic acid targets, where fluorescence is restored by nucleases that cleave the FRET reporters. However, the need for dual labelling and purification during manufacturing contributes to the high cost of FRET reporters. Here we demonstrate a low-cost silver nanocluster reporter that does not rely on FRET as the on/off switching mechanism, but rather on a cluster transformation process that leads to fluorescence color change upon nuclease digestion. Notably, a 90 nm red shift in emission is observed upon reporter cleavage, a result unattainable by a simple donor-quencher FRET reporter. Electrospray ionization–mass spectrometry results suggest that the stoichiometric change of the silver nanoclusters from Ag₁₃ (in the intact DNA host) to Ag₁₀ (in the fragments) is probably responsible for the emission colour change observed after reporter digestion. Our results demonstrate that DNA-templated silver nanocluster probes can be versatile reporters for detecting nuclease activities and provide insights into the interactions between nucleases and metallo-DNA nanomaterials.

荧光共振能量转移 (FRET) 报告基因通常用于核酸扩增测试的最后阶段，以指示核酸靶标的存在，其中荧光通过切割 FRET 报告基因的核酸酶恢复。然而，在制造过程中需要双重标记和纯化，导致 FRET 报告基因的成本较高。在这里，我们展示了一种低成本的银纳米簇报告基因，它不依赖于 FRET 作为开/关切换机制，而是依赖于簇转化过程，该过程会在核酸酶消化时导致荧光颜色变化。值得注意的是，在报告基因裂解时观察到发射发生 90 nm 红移，这是简单的供体淬灭 FRET 报告基因无法达到的结果。电喷雾电离-质谱结果表明，银纳米簇从Ag ₁₃（在完整DNA宿主中）到Ag ₁₀（在片段中）的化学计量变化可能是报告基因消化后观察到的发射颜色变化的原因。我们的结果表明，DNA 模板银纳米簇探针可以作为检测核酸酶活性的多功能报告基因，并提供对核酸酶和金属 DNA 纳米材料之间相互作用的见解。