On-site visual discrimination of transgenic food by water-soluble DNA-binding AIEgens

Development of affordable, simple and effective methods for rapid on-site identification of genetically modified organisms (GMO) is of importance due to public concern for transgenic food. In this paper, a visual discrimination method for transgenic food was developed based on a portable polymerase chain reaction (PCR) instrument and water-soluble AIE luminogens (AIEgens). The transgenes were extracted and amplified by the PCR device, further visualized by DNA-binding AIEgens 1,1,2,2-tetrakis[4-(2-bromo-ethoxy)phenyl] ethene (TTAPE) with a label-free approach. The lighted-up emission could be distinctly identified by the naked eye under a UV lamp or by a portable smartphone. The results showed that only transgenes can be visually detected, which confirmed the specificity of the proposed method. Besides, the whole PCR process was not affected by the addition of AIEgens. The portable system was successfully applied and validated for on-site screening and identification of transgenic papaya, corn and soybean samples. The proposed technique may serve as a general DNA fragment on-site visual discrimination platform for environmental and clinical applications.