柑橘黄龙病（HLB）被称为柑橘癌，其中Candidatus Liberibacter asiaticus（CLas）是引起HLB的最常见菌株。在这项研究中，我们报道了一种新型电化学发光（ECL）生物传感器，通过将滚环扩增（RCA）与 CRISPR/Cas12a 响应的智能 DNA 水凝胶相结合，可高灵敏地检测 CLas 外膜蛋白（Omp）基因。在存在靶标的情况下，通过 RCA 生成大量扩增子。扩增子通过与 crRNA 杂交激活 CRISPR/Cas12a 的反式切割活性，触发智能 DNA 水凝胶的响应，释放电极上封装的金银纳米簇 (AuAg NC)，从而导致 ECL 信号减弱。 ECL 强度变化 (I0 - I) 与 50 fM 至 5 nM 范围内的靶标浓度呈正相关，检测限为 40 fM。该传感器的性能还使用 10 个活柑橘叶样本（5 个 HLB 阴性和 5 个 HLB 阳性）进行了评估，结果与金标准 qPCR 结果非常一致。该传感策略扩展了 ECL 的多功能性，可高灵敏度地检测植物中不同水平的 dsDNA 或 ssDNA。

Citrus Huanglongbing (HLB) is known as the cancer of citrus, where Candidatus Liberibacter asiaticus (CLas) is the most prevalent strain causing HLB. In this study, we report a novel electrochemiluminescence (ECL) biosensor for the highly sensitive detection of the CLas outer membrane protein (Omp) gene by coupling rolling circle amplification (RCA) with a CRISPR/Cas12a-responsive smart DNA hydrogel. In the presence of the target, a large number of amplicons are generated through RCA. The amplicons activate the trans-cleavage activity of CRISPR/Cas12a through hybridizing with crRNA, triggering the response of smart DNA hydrogel to release the encapsulated AuAg nanoclusters (AuAg NCs) on the electrode and therefore leading to a decreased ECL signal. The ECL intensity change (I0 - I) is positively correlated with the concentration of the target in the range 50 fM to 5 nM, with a limit of detection of 40 fM. The performance of the sensor has also been evaluated with 10 samples of live citrus leaves (five HLB negative and five HLB positive), and the result is in excellent agreement with the gold standard qPCR result. The sensing strategy has expanded the ECL versatility for detecting varying levels of dsDNA or ssDNA in plants with high sensitivity.