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- 摘要
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- 实验方案
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Zero background and triple-signal amplified fluorescence aptasensor for antibiotics detection in foods
摘要： It's important to eliminate matrix interference for accurate detecting antibiotic residues in complex food samples. In this study, we designed a zero-backgrounded fluorescence aptasensor to achieve on-site detection of antibiotic residues, with chloramphenicol (CAP) as representative analyte. Moreover, a three stir-bars assisted target recycling system (TSBTR) was designed to achieve triple signal amplification and increase the sensitivity. The bars included one magnetic stir-bar modified with two kinds of long DNA chains, and two gold stir-bars modified with Y shape-duplex DNA probes respectively. In the presence of CAP, the target could recurrently react with the probes on the bars and replace a large amount of long DNA chains into supernatant. After then, the bars were taken out and SYBR green dye was added to the solution. The dye can specifically intercalate into the duplex structures of DNA chains to emit fluorescence while not emitting a signal in its free state. Under the optimized experimental conditions, a wide linear response range of 5 orders of magnitude from 0.001 ng mL?1 to 10 ng mL?1 was achieved with a detection limit of 0.033 pg mL?1 CAP. The assay was successfully employed to detect CAP in food samples (milk & fish) with consistent results with ELISA's. High selectivity and sensitivity were attributed to the zero background signal and triple signal-amplification strategy. Moreover, the detection time can be shortened to 40 min due to that three signal amplified process can occur simultaneously. The fluorescent aptasensor was also label- and enzyme-free. All these ensure the platform to be rapid, cost-effective, easily-used, and is especially appropriate for detection antibiotics in food safety.
关键词： Three stir-bars assisted target recycling,Triple signal amplification,Zero background signal,Fluorescence aptasensor,Antibiotics
更新于2025-11-19 16:46:39
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Building a Fluorescent Aptasensor Based on Exonuclease-Assisted Target Recycling Strategy for One-Step Detection of T-2 Toxin
摘要： In this work, a rapid and accurate assay was successfully developed for T-2 toxin detection based on exonuclease-catalyzed target recycling strategy. Upconversion nanoparticles (UCNPs) were conjugated with T-2 aptamer and used as signal probes, while magnetic nanoparticles (MNPs) were conjugated with the complementary DNA of T-2 aptamer (cDNA) and used as capture probes. The results reveled that good linear correlation (R2 = 0.9988) was achieved for T-2 toxin detection over the concentration range of 0.1–100 ng/mL with a detection limit as low as 0.035 ng/mL (S/N = 3). In addition, the reliability of the proposed method was also applied to the determination of T-2 toxin contents in real food samples and the average recoveries ranged from 95.97 to 104.00%. The sensing platform developed in our study demonstrated great potential for simple and sensitive detection of T-2 toxin contents in food samples.
关键词： T-2 toxin,Food safety,Fluorescence,Aptasensor,Target recycling strategy
更新于2025-09-23 15:23:52