Abstract：
BACKGROUND: 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.
RESULTS: 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.
CONCLUSIONS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
摘要：
背景：妥布霉素（TOB），一种人类生活中必需的氨基糖苷类抗生素，由于其在环境中的残留而构成潜在威胁。首要关注的是TOB超标对人体肾脏的不利影响,听力,和其他器官，严重影响人类健康。构建灵敏的电化学平台,实现简单快速的痕量检测至关重要。在这里，为了提高环境中TOB检测的灵敏度，并减轻与残留抗生素相关的风险，开发了一种超灵敏的电化学aptasensor。
结果：传感器采用涉及催化发夹组装（CHA）和外切核酸酶III（ExoIII）的双循环扩增策略，以实现有效的信号扩增。同时,通过将金纳米线（AuNWs）结合到还原的氧化石墨烯（PDA-rGO）的表面上来优化电极性能。具体来说,在TOB在场的情况下,与适体(Apt)结合，dsDNA解离，释放cDNA到开放发夹1（HP1），并在发夹2（HP2）的参与下启动CHA周期。ExoIII剪切HP1/HP2复合物中的HP1，释放HP2再次参与CHA周期。最终,通过与剪切的HP1杂交,显著量的信号标记物保留在电极上,产生稳健的电信号。
结论：通过信号放大策略，aptasensor设计提供了0.005-500nM的广泛线性范围，TOB的低检测限为0.112pM。值得一提的是，aptasensor显示出良好的稳定性，特异性，和再现性，并已成功应用于实际样品，证明其在实际应用中的实用性。
结果：传感器采用涉及催化发夹组装（CHA）和外切核酸酶III（ExoIII）的双循环扩增策略，以实现有效的信号扩增。同时,通过将金纳米线（AuNWs）结合到还原的氧化石墨烯（PDA-rGO）的表面上来优化电极性能。具体来说,在TOB在场的情况下,与适体(Apt)结合，dsDNA解离，释放cDNA到开放发夹1（HP1），并在发夹2（HP2）的参与下启动CHA周期。ExoIII剪切HP1/HP2复合物中的HP1，释放HP2再次参与CHA周期。最终,通过与剪切的HP1杂交,显著量的信号标记物保留在电极上,产生稳健的电信号。
结论：通过信号放大策略，aptasensor设计提供了0.005-500nM的广泛线性范围，TOB的低检测限为0.112pM。值得一提的是，aptasensor显示出良好的稳定性，特异性，和再现性，并已成功应用于实际样品，证明其在实际应用中的实用性。
