Rapid detection of target foodborne pathogens plays more and more significant roles in food safety, which requires the efficiency, sensitivity, and accuracy. In this research, we proposed a new strategy of isothermal-molecular-amplification integrated with lateral-flow-strip for rapid detection of Salmonella without traditional enrichment-culture. The designed syringe-assisted-filtration can contribute to simultaneous collection and concentration of target bacterium from vegetable samples in just 3 min, resolving the drawbacks of traditional random sampling protocols. After simple and convenient ultrasonication, samples can be directly amplified at 39 ℃ in 25 min and the amplicons are qualitatively and quantitatively analyzed with the designed lateral-flow-strip in 5 min. Finally, satisfied results have been achieved within 40 min, which greatly improve the efficiency while the accuracy is also guaranteed. Furthermore, all detection steps can be completed under instrument-free conditions. This method will hold great promise for target pathogen detection in the resource-limited district, or for emergency on-site identification.

In order to enhance the flavor of chafing dish and increase the attraction of consumers, the poppy shell is reported to be illegally added to the condiments of chafing dish. In this research, a rapid, simple, and convenient method based on the classic immunochromatographic lateral flow strip (LFS) with gold nanoparticles (GNPs) labeling was developed for easy monitoring of morphine (MOP), an effective component of poppy shell. Under optimized conditions, this developed LFS can well realize the detection of target MOP in the condiments of chafing dish in less than 10 min without any complicated pre-treatments. The limit of detection (LOD) can be achieved as low as 0.1 ppb for standard MOP or the MOP spiked condiments of chafing dish. All these results of the research strongly demonstrate that this established LFS method can be successfully applied in practical rapid and accurate on-site screening of poppy shell in condiments of chafing dish.

We report the design of a sensitive, electrochemical aptasensor for detection of ochratoxin A (OTA) with an extraordinary tunable dynamic sensing range. This electrochemical aptasensor is constructed based on the target induced aptamer-folding detection mechanism and the recognition between OTA and its aptamers results in the conformational change of the aptamer probe and thus signal changes for measurement. The dynamic sensing range of the electrochemical aptasensor is successfully tuned by introduction of free assistant aptamer probes in the sensing system. Our electrochemical aptasensor shows an extraordinary dynamic sensing range of 11-order magnitude of OTA concentration from 10⁻⁸ to 10² ng/g. Of great significance, the signal response in all OTA concentration ranges is at the same current scale, demonstrating that our sensing protocol in this research could be applied for accurate detections of OTA in a broad range without using any complicated treatment of signal amplification. Finally, OTA spiked red wine and maize samples in different dynamic sensing ranges are determined with the electrochemical aptasensor under optimized sensing conditions. This tuning strategy of dynamic sensing range may offer a promising platform for electrochemical aptasensor optimizations in practical applications.