1. A dual-cycle amplification-based electrochemical platform for sensitive detection of tobramycin.
- Author
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Zhang, Baozhong, Ma, Xinyue, Xie, Lingling, Li, Xiquan, Chen, Lingyun, and He, Baoshan
- Subjects
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TOBRAMYCIN , *EXONUCLEASES , *ELECTRODE performance , *HAIRPIN (Genetics) , *DETECTION limit , *GRAPHENE oxide - Abstract
Tobramycin (TOB), an essential aminoglycoside antibiotic in human life, poses potential threats due to its residues in the environment. The primary concern is the adverse impact of excessive TOB on human kidneys, hearing, and other organs, significantly affecting human health. Constructing a sensitive electrochemical platform for simple and rapid trace detection is crucial. Herein, to enhance the sensitivity of TOB detection in the environment and mitigate the risks associated with residual antibiotics, an ultrasensitive electrochemical aptasensor was developed. The sensor employs a dual-cycle amplification strategy involving catalytic hairpin assembly (CHA) and exonuclease III (Exo III) for efficient signal amplification. Simultaneously, the electrode performance was optimized by incorporating gold nanowires (AuNWs) onto the surface of reduced graphene oxide (PDA-rGO). Specifically, in the presence of TOB, which binds to the aptamer (Apt), dsDNA dissociates, releasing cDNA to open hairpin 1 (HP1) and initiate the CHA cycle with the participation of hairpin 2 (HP2). Exo III shears HP1 in the HP1/HP2 complex, freeing HP2 to participate in the CHA cycle again. Ultimately, a significant amount of signal label is retained on the electrode by hybridizing with sheared HP1, generating a robust electrical signal. Through the signal amplification strategy, the aptasensor design provides a broad linear range of 0.005–500 nM, with a low detection limit of 0.112 pM for TOB. It is worth mentioning that the aptasensor displayed favorable stability, specificity, and reproducibility, and has been successfully applied to practical samples, demonstrating its utility in practical applications. [Display omitted] • The utilization of a cascade amplification strategy involving CHA and Exo III enables efficient signal amplification. • AuNWs/PDA-rGO composites were designed as substrate materials to optimize the electrodes. • The sensor demonstrates a low detection limit of 0.112 pM for TOB and possesses a broad linear range. • The developed sensor facilitates highly sensitive and selective detection of TOB in real samples. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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