The rapid identification of pathogenic microorganisms plays a crucial role in the timely diagnosis and treatment strategies during a global pandemic, especially in resource-limited area. Herein, we present a sensitive biosensor strategy depended on botulinum neurotoxin type A light chain (BoNT/A LC) activated complex assay (BACA). BoNT/A LC, the surrogate of BoNT/A which embodying the most potent biological poisons, could serve as an ultrasensitive signal reporter with high signal-to-noise ratio to avoid common strong background response, poor stability and low intensity of current biosensor methods. A nanoparticle hybridization system, involving specific binding probes that recognize pathogenic 16S rRNAs or SARS-CoV-2 gene site, was developed to measure double-stranded biotinylated target DNA containing a single-stranded overhang using Fluorescence Resonance Energy Transfer (FRET)-based assay and colorimetric method. The method is validated widely by six different bacteria strains and severe acute respiratory related coronavirus 2 (SARS-CoV-2) nucleic acid, demonstrating a single cell or 1 aM nucleic acid detecting sensitivity. This detection strategy offers a solution for general applications and has a great prospect to be a simple instrument-free colorimetric tool, especially when facing public health emergency.

病原微生物的快速鉴定在全球大流行期间的及时诊断和治疗策略中起着至关重要的作用，特别是在资源有限的地区。在此，我们提出了一种依赖于 A 型肉毒杆菌神经毒素轻链 (BoNT/A LC) 激活复合物测定 (BACA) 的灵敏生物传感器策略。BoNT/A LC 是 BoNT/A 的替代品，具有最强的生物毒性，可作为高信噪比的超灵敏信号报告器，避免目前生物传感器方法常见的强背景响应、稳定性差和强度低的问题. 一种纳米粒子杂交系统，包括识别致病性 16S rRNA 或 SARS-CoV-2 基因位点的特异性结合探针，被开发用于使用基于荧光共振能量转移 (FRET) 的测定和比色法测量含有单链悬垂的双链生物素化靶 DNA。该方法通过六种不同的细菌菌株和严重急性呼吸道相关冠状病毒 2 (SARS-CoV-2) 核酸进行了广泛验证，证明了单细胞或 1 aM 核酸的检测灵敏度。这种检测策略为一般应用提供了解决方案，并有很大的前景成为一种简单的无仪器比色工具，特别是在面临公共卫生紧急情况时。展示单细胞或 1 aM 核酸检测灵敏度。这种检测策略为一般应用提供了解决方案，并有很大的前景成为一种简单的无仪器比色工具，特别是在面临公共卫生紧急情况时。展示单细胞或 1 aM 核酸检测灵敏度。这种检测策略为一般应用提供了解决方案，并有很大的前景成为一种简单的无仪器比色工具，尤其是在面临公共卫生紧急情况时。