Department of Bioproducts and Biosystems Engineering, University of Minnesota Twin Cities, MN, 55108-6005, USA.
Department of Bioproducts and Biosystems Engineering, 2004 Folwell Avenue, Saint Paul, MN, 5511, USA.
Adv Healthc Mater. 2018 Jul;7(13):e1701506. doi: 10.1002/adhm.201701506. Epub 2018 Apr 3.
With the global rise of antimicrobial resistance, rapid screening and identification of low concentrations of microorganisms in less than 1 h becomes an urgent technological need for evidence-based antibiotic therapy. Although many commercially available techniques are labeled for rapid microbial detection, they often require 24-48 h of cell enrichment to reach detectable levels. Here, it is shown that the widely used reducing agent tris(2-carboxyethyl)phosphine (TCEP) can also act as a powerful oxidant on gold nanoplates and subsequently lead to a strong catalysis of luminol chemiluminescence. The catalytic reaction results in up to 100-fold signal enhancement and unprecedented stable luminescence for up to 10 min. However, when TCEP is exposed to microorganisms, it is oxidized by the microbial surface proteins and loses its catalytic properties, leading to a decrease in chemiluminescence. The competitive interaction of TCEP with Au nanoplates and microorganisms is used to introduce a homogenous rapid detection method that allows microbial screening in less than 10 min with a limit of detection down to 100 cfu mL . Furthermore, the concept of microbial macromolecular shielding using antibody-conjugated polymers is introduced. The combination of TCEP redox activity and macromolecular shielding enables specific microbial identification within 1 h, without preconcentration, cell enrichment, or heavy equipment other than a hand-held luminometer. The technique is demonstrated by specific detection of methicillin-resistant Staphylococcus aureus in environmental and urine samples containing a mixture of microorganisms.
随着全球范围内抗菌药物耐药性的上升，在 1 小时内快速筛选和鉴定低浓度微生物成为基于证据的抗生素治疗的迫切技术需求。虽然许多市售技术被标记为用于快速微生物检测，但它们通常需要 24-48 小时的细胞富集才能达到可检测水平。在这里，我们展示了广泛使用的还原剂三(2-羧乙基)膦（TCEP）也可以在金纳米板上作为一种强大的氧化剂，并随后导致鲁米诺化学发光的强烈催化。催化反应导致信号增强高达 100 倍，并且在长达 10 分钟的时间内具有前所未有的稳定发光。然而，当 TCEP 暴露于微生物时，它被微生物表面蛋白氧化，失去其催化特性，导致化学发光减弱。TCEP 与 Au 纳米板和微生物的竞争相互作用被用于引入一种均相快速检测方法，该方法允许在不到 10 分钟的时间内进行微生物筛选，检测限低至 100 cfu mL 。此外，还引入了使用抗体偶联聚合物进行微生物大分子屏蔽的概念。TCEP 氧化还原活性和大分子屏蔽的结合使能够在 1 小时内进行特定微生物的鉴定，而无需预浓缩、细胞富集或除手持式光度计之外的任何重型设备。该技术通过在含有混合微生物的环境和尿液样本中特异性检测耐甲氧西林金黄色葡萄球菌得到了验证。
