Aptamer-based DNAzyme walker electrochemical biosensing strategy for Acinetobacter baumannii detection

Linhong Cao; Tianyu Wang; Jingling Xie; Yihua Wang; Yaxin Huang; Sijian Luo; Xiaoting Zhan; Hui Jiang; Liuxin Ran; Xing Jin; Jinbo Liu; Baolin Li

doi:10.1016/j.bioelechem.2024.108895

Aptamer-based DNAzyme walker electrochemical biosensing strategy for Acinetobacter baumannii detection

Bioelectrochemistry. 2024 Dec 28:163:108895. doi: 10.1016/j.bioelechem.2024.108895. Online ahead of print.

Authors

Linhong Cao¹, Tianyu Wang¹, Jingling Xie¹, Yihua Wang¹, Yaxin Huang¹, Sijian Luo¹, Xiaoting Zhan¹, Hui Jiang¹, Liuxin Ran², Xing Jin², Jinbo Liu³, Baolin Li⁴

Affiliations

¹ Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou 646000, Sichuan, China; Sichuan Province Engineering Technology Research Center of Molecular Diagnosis of Clinical Diseases, China; Molecular Diagnosis of Clinical Diseases Key Laboratory of Luzhou, Sichuan, China.
² Department of Medical Laboratory Medicine, Southwest Medical University, Sichuan, China.
³ Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou 646000, Sichuan, China; Sichuan Province Engineering Technology Research Center of Molecular Diagnosis of Clinical Diseases, China; Molecular Diagnosis of Clinical Diseases Key Laboratory of Luzhou, Sichuan, China. Electronic address: [email protected].
⁴ Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou 646000, Sichuan, China; Sichuan Province Engineering Technology Research Center of Molecular Diagnosis of Clinical Diseases, China; Molecular Diagnosis of Clinical Diseases Key Laboratory of Luzhou, Sichuan, China. Electronic address: [email protected].

PMID: 39742713
DOI: 10.1016/j.bioelechem.2024.108895

Abstract

In this study, an innovative electrochemical biosensor was developed for the rapid, specific, and sensitive detection of Acinetobacter baumannii without the need for sample pretreatment. The biosensor utilized an aptamer as a specific capture probe for A. baumannii and employed a self-powered DNAzyme walker cleavage cycle reaction to achieve signal amplification. Upon introduction of the target bacteria, the aptamer captured the bacteria and released the Trigger, activating the DNAzyme to cleave the substrate chain containing methylene blue (MB). This led to the release of MB-labeled DNA fragments from the electrode surface, resulting in a significant decrease in the square wave voltammetry (SWV) signal of MB on the sensing platform. The limit of detection (LOD) for A. baumannii was determined to be 30 CFU/mL, enabling discrimination of the target bacteria from other common clinical isolates. Furthermore, the biosensor's potential for real sample analysis was demonstrated in cerebrospinal fluid (CSF), showcasing its efficacy and versatility as a biosensing tool with wide-ranging applications in disease diagnosis and bioanalysis.

Keywords: Acinetobacter baumannii; Aptamer; DNAzyme-walker; Electrochemical biosensor.