Functional nucleic acid lateral flow magnetic biosensor based on blocking the super PCR and magnetic test strip for rapid detection of genetically modified maize MON810

Although PCR is a typical temperature-variable amplification technique for nucleic acids, it still faces challenges in rapid screening, such as low speed, poor sensitivity, inferior visualization, and weak stability. In this paper, a universal functional nucleic acid (FNA) lateral flow magnetic biosensor was constructed using blocking super PCR (BS-PCR) and a magnetic test strip (MTS). In theory, the visualized and magnetic output of dsDNA-based amplicons were achieved via ssDNA/dsDNA conversion by blocking linkers in the PCR primers and magnetic probes. In application, high-speed, super-sensitive, highly stable rapid screening was realized by taking advantage of the speediness of the super PCR reactor and the anti background interference, visualization and high stability of magnetic signal readout. The genetically modified maize MON810 was selected as a double-stranded model target, while 5-min BS-PCR and 5 min magnetic signal readouts achieved the screening results within 10 min. Furthermore, the exponential PCR amplification and magnetic-based sensibilization improved the sensitivity to a single copy. This biosensor is simple and portable, with significant potential for rapid on-site screening.(c) 2022 Elsevier B.V. All rights reserved.