The rapid and cost- effective detection of bacteria is of great importance in various fields. Herein, a novel colorimetric detection method for Gram-negative bacteria based on the inhibition of the aggregation of 4-mercaptophenylboronic acid functionalized AgNPs (MPBA-AgNPs) was demonstrated. MPBA, one of the boronic acid derivative, which could react with the cis-diol groups contained in saccharides on the bacteria cells, was used as the recognition molecule for bacteria detection. The aggregation of MPBA-AgNPs could be inhibited by bacterial cells, resulting in different color change, which could be distinguished with UV–vis spectrometer and the naked eye. The concentration of E. coli, a model of Gram-negative bacteria, could be determined in a dynamic range from 5 × 10⁴ cfu mL⁻¹ to 1 × 10⁷ cfu mL⁻¹ with a LOD of 0.9 × 10⁴ cfu mL⁻¹ with fast response of 20 min. Meanwhile, a smartphone based measuring analysis was established to make it suitable for routine laboratory applications. Moreover, the concept of the MPBA-AgNPs based colorimetric strategy could be expanded to other Gram-negative bacteria suggesting a universal platform for bacterial assay.

快速且经济高效地检测细菌在各个领域都非常重要。本文中，基于抑制4-巯基苯基硼酸官能化的AgNPs（MPBA-AgNPs）的聚集，革兰氏阴性细菌的新型比色检测方法得到了证明。可以与细菌细胞糖中的顺式-二醇基团反应的硼酸衍生物之一MPBA被用作细菌检测的识别分子。MPBA-AgNPs的聚集可以被细菌细胞抑制，导致不同的颜色变化，这可以通过紫外可见分光光度计和肉眼来区分。革兰氏阴性菌模型大肠杆菌的浓度可以在5×10的动态范围内确定⁴  cfu mL ^-1至1×10 ⁷  cfu mL ^-1，LOD为0.9×10 ⁴  cfu mL ^-1，响应时间为20分钟。同时，建立了基于智能手机的测量分析，使其适合常规实验室应用。此外，基于MPBA-AgNPs的比色策略的概念可以扩展到其他革兰氏阴性细菌，这为细菌测定提供了一个通用平台。