这项研究报告了一种光催化电化学aptasensor的开发,用于通过利用SYBRGreenI(SG)和化学剥离MoS2(ce-MoS2)作为协同信号放大平台来检测水中氯霉素(CAP)抗生素残留。将Au纳米颗粒(AuNP)电沉积到氧化铟锡(ITO)电极的表面上。之后,硫醇盐修饰的cDNA,也被称为捕获DNA,与适体结合。随后,将光敏的SG分子和ce-MoS2纳米材料插入所得双链DNA(dsDNA)的凹槽中。暴露于光后光催化过程的活化导致单线态氧的产生。单线态氧有效地分裂了dsDNA,导致[Fe(CN)6]3-/4-的电流显着增强。当CAP出现时,SG分子和ce-MoS2都脱离了dsDNA,关闭了光敏反应,导致[Fe(CN)6]3-/4-电流显着降低。在最优条件下,aptasensor表现出[Fe(CN)6]3-/4-电流与20至1000nM的CAP对数浓度之间的线性关系,检测限(3σ)为3.391nM。在存在干扰抗生素的情况下,aptasensor还表现出对CAP的良好选择性,比如四环素,链霉素,左氧氟沙星,环丙沙星,和磺胺二甲氧嘧啶.此外,使用拟议的aptasensor分析天然水样的结果与使用液相色谱-质谱仪获得的结果一致。因此,其简单性和高选择性,这种aptasensor可以通过替换基于光敏作用的适体来检测环境水样中的替代抗生素。
This study reports the development of a photocatalytic electrochemical aptasensor for the purpose of detecting chloramphenicol (CAP) antibiotic residues in water by utilizing SYBR Green I (SG) and chemically exfoliated MoS2 (ce-MoS2) as synergistically signal-amplification platforms. The Au nanoparticles (AuNPs) were electrodeposited onto the surface of an indium tin oxide (ITO) electrode. After that, the thiolate-modified cDNA, also known as capture DNA, was combined with the aptamer. Subsequently, photosensitized SG molecules and ce-MoS2 nanomaterial were inserted into the groove of the resultant double-stranded DNA (dsDNA). The activation of the photocatalytic process upon exposure to light resulted in the generation of singlet oxygen. The singlet oxygen effectively split the dsDNA, resulting in significant enhancement in the current of [Fe(CN)6]3-/4-. When the CAP was present, both SG molecules and ce-MoS2 broke away from the dsDNA, which turned off the
photosensitization response, leading to significant reduction in the current of [Fe(CN)6]3-/4-. Under the optimal conditions, the aptasensor exhibited a linear relationship between the current of [Fe(CN)6]3-/4- with logarithmic concentrations of CAP from 20 to 1000 nM, with a detection of limit (3σ) of 3.391 nM. The aptasensor also demonstrated good selectivity towards CAP in the presence of interfering antibiotics, such as tetracycline, streptomycin, levofloxacin, ciprofloxacin, and sulfadimethoxine. Additionally, the results obtained from the analysis of natural water samples using the proposed aptasensor were consistent with the findings acquired through the use of a liquid chromatograph-mass spectrometer. Therefore, with its simplicity and high selectivity, this aptasensor can potentially detect alternative antibiotics in environmental water samples by replacing the aptamers based on
photosensitization.