Sonam Kumari, Monika Nehra, Shikha Jain, Annu Sheokand, Neeraj Dilbaghi, Ganga Ram Chaudhary, Ki-Hyun Kim, Sandeep Kumar
{"title":"Luminescent Cu nanoclusters–encapsulated ZIF-8 as on–off–on fluorescent probe for efficient and selective quantification of E. coli","authors":"Sonam Kumari, Monika Nehra, Shikha Jain, Annu Sheokand, Neeraj Dilbaghi, Ganga Ram Chaudhary, Ki-Hyun Kim, Sandeep Kumar","doi":"10.1007/s00604-024-06905-0","DOIUrl":null,"url":null,"abstract":"<div><p>Rapid and accurate detection of <i>Escherichia coli</i> (<i>E. coli</i>) is critical for maintaining water quality, and protecting aquatic ecosystems and public health. This research focuses on the development of a Förster resonance energy transfer (FRET)–based “turn-on” fluorescent nanosensor for real time, sensitive detection of <i>E. coli</i>. Copper nanoclusters–encapsulated metal organic frameworks (CuNCs@ZIF-8) were sythesized as a fluorescent donor with excellent luminescence properties. Further, MnO<sub>2</sub> nanospheres were synthesized as a receptor with good adsorption and quenching abilities. This novel nanoconjugate (CuNCs@ZIF-8@ MnO<sub>2</sub>) was employed for the construction of a sensitive, accurate, and rapid sensing platform against <i>E. coli</i> in water on the basis of p-benzoquinone/hydroquinone (p-BQ/HQ) redox pair formation. Fluorescence is quenched by energy transfer when MnO<sub>2</sub> nanospheres are added to CuNCs@ZIF-8. Upon contact with <i>E. coli</i>, NADH-quinone reductase converts p-BQ to HQ, which reduces MnO<sub>2</sub> to Mn<sup>2+</sup>, releasing the nanospheres and restoring fluorescence in the composite. Based on this FRET ON–OFF-ON fluorescent probe, <i>E. coli</i> can be detected across a broad concentration range (5 × 10<sup>1</sup> to 5 × 10<sup>5</sup> CFU/mL), with a detection limit as low as 8 CFU/mL within 50 min. The sensor’s practicality was verified through the investigation of <i>E. coli</i> in real water samples, with recoveries in the range 94.3 to 106.5%. This approach offers an efficient method for on-site detection and quantification of <i>E. coli</i> in both environment and food safety domains.</p><h3>Graphical abstract</h3>\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":705,"journal":{"name":"Microchimica Acta","volume":"192 2","pages":""},"PeriodicalIF":5.3000,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microchimica Acta","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s00604-024-06905-0","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Rapid and accurate detection of Escherichia coli (E. coli) is critical for maintaining water quality, and protecting aquatic ecosystems and public health. This research focuses on the development of a Förster resonance energy transfer (FRET)–based “turn-on” fluorescent nanosensor for real time, sensitive detection of E. coli. Copper nanoclusters–encapsulated metal organic frameworks (CuNCs@ZIF-8) were sythesized as a fluorescent donor with excellent luminescence properties. Further, MnO2 nanospheres were synthesized as a receptor with good adsorption and quenching abilities. This novel nanoconjugate (CuNCs@ZIF-8@ MnO2) was employed for the construction of a sensitive, accurate, and rapid sensing platform against E. coli in water on the basis of p-benzoquinone/hydroquinone (p-BQ/HQ) redox pair formation. Fluorescence is quenched by energy transfer when MnO2 nanospheres are added to CuNCs@ZIF-8. Upon contact with E. coli, NADH-quinone reductase converts p-BQ to HQ, which reduces MnO2 to Mn2+, releasing the nanospheres and restoring fluorescence in the composite. Based on this FRET ON–OFF-ON fluorescent probe, E. coli can be detected across a broad concentration range (5 × 101 to 5 × 105 CFU/mL), with a detection limit as low as 8 CFU/mL within 50 min. The sensor’s practicality was verified through the investigation of E. coli in real water samples, with recoveries in the range 94.3 to 106.5%. This approach offers an efficient method for on-site detection and quantification of E. coli in both environment and food safety domains.
期刊介绍:
As a peer-reviewed journal for analytical sciences and technologies on the micro- and nanoscale, Microchimica Acta has established itself as a premier forum for truly novel approaches in chemical and biochemical analysis. Coverage includes methods and devices that provide expedient solutions to the most contemporary demands in this area. Examples are point-of-care technologies, wearable (bio)sensors, in-vivo-monitoring, micro/nanomotors and materials based on synthetic biology as well as biomedical imaging and targeting.