Portable fluoride-selective electrode as signal transducer for sensitive and selective detection of trace antibiotics in complex samples.
Ion-selective electrodes (ISE) can rapidly, sensitively detect their corresponding ions and are suitable for field testing. However, most ISE methods cannot detect other targets directly which limits their practice application. Herein, we established an aptamer-sensing platform to detect organic small molecule using a portable fluoride-selective electrode (FSE). To achieve the purpose, novel signal tags were fabricated based on nano metal-organic frameworks (NMOF) encapsulating F- and labeling aptamers. They were then immobilized on one stir-bar. Subsequently, a double stir-bars (bar-a and b) assisted target recycling strategy was designed to convert organic small molecular target to F- for signal development and amplification. The movement of tags from bar-a to b can be triggered by the analytes. After reaction, the transferred signal tags in bar-b were washed and released F- which can be measured by FSE for qualification of the target. The assay was evaluated to detect kanamycin or chloramphenicol which was employed as the representatives of organic small molecular with a low detection limit of 0.35 nmol L-1 or 0.46 nmol L-1, respectively. Satisfactory performance was observed in complex sample analysis of kanamycin (milk, fish, urine and serum) with a recovery of 91-108% and an RSD (n = 6) <5%. The proposed method broadens the application of traditional FSE to the detection of organic small molecule. And the employment of NMOF which has higher encapsulating capacity of F- for preparing signal tags can be extended to FSE based aptasensors.
['Huang|Shengfeng|S|', 'Gan|Ning|N|', 'Zhang|Xinyu|X|', 'Wu|Yongxiang|Y|', 'Shao|Yong|Y|', 'Jiang|Zhengjin|Z|', 'Wang|Qiqin|Q|']
D000818:Animals D000900:Anti-Bacterial Agents D052157:Aptamers, Nucleotide D015374:Biosensing Techniques D002701:Chloramphenicol D005504:Food Analysis D007612:Kanamycin D057230:Limit of Detection D000073396:Metal-Organic Frameworks D008892:Milk
Fluoride-selective electrode aptasensors Organic small molecular detection Toehold strand displacement reaction