Aptamer-based DNA-catalyzed amplification strategy for sensitive fluorescence resonance energy transfer detection of Acinetobacter baumannii

• Published in: Talanta (Oxford) 2023-04, Vol.255, p.124212-124212, Article 124212
• Main Authors: Xie, Jingling, Jiang, Hui, Zhao, Yuanqing, Zhong, Min, Jin, Xinrui, Zhu, Zixin, Baolin Li, Guo, Jinglan, Zhang, Limei, Liu, Jinbo
• Format: Article
• Language: English
• Subjects: Acinetobacter baumannii; Acinetobacter baumannii - genetics; Aptamers, Nucleotide - genetics; Biosensing Techniques - methods; Catalysis; DNA; DNA-catalyzed amplification; Fluorescence resonance energy transfer; Fluorescence Resonance Energy Transfer - methods; Graphene oxide
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.124212

Acinetobacter baumannii (A. baumannii) is a common pathogen that causes hospital-acquired infections and is resistant to a wide variety of antibiotics. Consequently, the rapid and highly sensitive detection of A. baumannii is required during the early stages of infection. Therefore, we developed a DNA-catalyzed amplification mechanism based on aptamers, combined with a novel fluorescence resonance energy transfer (FRET) method based on graphene oxide (GO), for the detection of A. baumannii. In the presence of A. baumannii, an aptamer bound to A. baumannii, releasing the template strand, which triggered an entropy-driven catalysis (EDC) reaction. One EDC product was then used as the catalyst for catalytic hairpin assembly (CHA) on a GO nanosheet. Finally, the GO released a huge amount of FAM-labeled DNA duplices, which could be detected with FRET. This strategy circumvented the extraction of nucleic acids and was easy to execute, with a detection time of ≤1.5 h. The detection of A. baumannii with this method ranges from 5 cfu/mL to 1 × 105 cfu/mL, with a detection limit of 1.1 cfu/mL. The method was sufficiently sensitive and specific to detect A. baumannii rapidly in cerebrospinal fluid. In summary, our strategy provides a new option for the early detection and point-of-care testing (POCT) of A. baumannii infections, allowing their earlier and more precise treatment. [Display omitted] •An FERT biosensor based on GO was designed for early detection of A. baumannii detection.•Aptamer recognition of the target omitted the nucleic acid extraction step.•Combined EDC with CHA generated a powerful DNA amplification signal.•Different targets can be detected by slightly altering a few bases in the DNA sequences.