Amornwairat Pinyapat, Pissuwan Dakrong
Materials and Engineering Graduate Program, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Payathai, Bangkok 10400, Thailand.
Nanobiotechnology and Nanobiomaterials Research Laboratory, School of Materials Science and Innovation, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Payathai, Bangkok 10400, Thailand.
ACS Omega. 2023 Mar 30;8(14):13456-13464. doi: 10.1021/acsomega.3c01205. eCollection 2023 Apr 11.
Gold nanoparticles (GNPs) have been used as detection probes for rapid and sensitive detection of various analytes, including bacteria. Here, we demonstrate a simple strategy for bacterial detection using GNPs functionalized with 4-mercaptophenylboronic acid (4-MPBA). 4-MPBA can interact with peptidoglycan or lipopolysaccharides present in bacterial organelles. After the addition of a high concentration of sodium hydroxide (NaOH), the functionalization of the surface of 50 nm GNPs with 4-MPBA (4-MPBA@GNPs) in the presence of polyethylene glycol results in a color change because of the aggregation of 4-MPBA@GNPs. This color change is dependent on the amount of bacteria present in the tested samples. () K-12 and () are used as Gram-negative and Gram-positive bacterial models, respectively. The color change can be detected within an hour by the naked eye. A linear relationship is observed between bacterial concentrations and the absorbance intensity at 533 nm; values of 0.9152 and 0.8185 are obtained for K-12 and , respectively. The limit of detection of K-12 is ∼2.38 × 10 CFU mL and that of is ∼4.77 × 10 CFU mL. This study provides a promising approach for the rapid detection of target Gram-negative and Gram-positive bacteria.
金纳米颗粒（GNPs）已被用作检测探针，用于快速、灵敏地检测包括细菌在内的各种分析物。在此，我们展示了一种使用用4-巯基苯硼酸（4-MPBA）功能化的GNPs进行细菌检测的简单策略。4-MPBA可以与细菌细胞器中存在的肽聚糖或脂多糖相互作用。在加入高浓度氢氧化钠（NaOH）后，在聚乙二醇存在下，用4-MPBA对50 nm GNPs表面进行功能化（4-MPBA@GNPs）会导致颜色变化，这是由于4-MPBA@GNPs的聚集。这种颜色变化取决于测试样品中存在的细菌数量。（）K-12和（）分别用作革兰氏阴性和革兰氏阳性细菌模型。肉眼可在一小时内检测到颜色变化。在细菌浓度与533 nm处的吸光度强度之间观察到线性关系；K-12和的R²值分别为0.9152和0.8185。K-12的检测限约为2.38×10 CFU/mL，的检测限约为4.77×10 CFU/mL。本研究为快速检测目标革兰氏阴性和革兰氏阳性细菌提供了一种有前景的方法。
