A Label-Free Electrochemical Impedance Genosensor Coupled with Recombinase Polymerase Amplification for Genetically Modified Maize Detection

Abstract

As the cultivation scale of genetically modified (GM) crops strongly increases, a convenient DNA assay is highly demanded in resource-limited areas. A label-free electrochemical impedance (EI) genosensor using gold carbon dots (GCDs) was developed with easy-to-use portable device. GCDs were used to modify screen-printed carbon electrode and immobilize capture probes by conducting a simple protocol. After the amplification products anchored on the sensor surface via hybridization reactions, the EI signal increased due to the formation of biocomplex hampering the interfacial electron transfer. Under the optimal conditions, the proposed genosensor coupled with recombinase polymerase amplification (RPA) could detect maize Ruifeng12-5 in a linear range of 0.10–5.0% with a detection limit of 0.10%. In addition, combined with a one-step extraction and RPA amplification, the proposed sensor device can be applied in resource-limited laboratories without expensive instruments or professionals. Therefore, the developed method provides an easy-to-use and sensitive platform for GM organism detection.

Research Progress of Nucleic Acid Detection Technology for Genetically Modified Maize

“…Such combinations include an ultrasensitive test strip combined with the RPA and CRISPR/Cas12a systems for the rapid detection of GM crops [142,181]. Recombinant polymerase amplification combined with a label-free electrochemical impedance gene sensor has been used to detect GM maize [159]. The third direction is the development of new technologies, building new detection systems in principle and form, and changing and discovering new available materials, which may require long-term research.…”

Review of Electrochemical Biosensors for Food Safety Detection

“…Cui et al [ 73 ] developed a label-free electrochemical impedance gene sensor using gold carbon dots (GCDs) and an easy-to-use portable device. It consists of a handheld electrochemical impedance (EI) analyzer equipped with a coin-sized SPCE.…”

“… Fabrication process of EI gene sensor based on GCD (Reprinted with permission from Ref. [ 73 ]. 2022, Cui et al).…”

Rapid Identification of HSA Genetically Modified Goats by Combining Recombinase Polymerase Amplification (RPA) with Lateral Flow Dipstick (LFD)

“…These results indicate that the RPA-LFD assay can successfully distinguish its target DNA from that of non-transgenic animals without cross-reaction or false positive signals were observed, and that the HSA transgenic RPA-LFD assay is specific for the detection of its corresponding target. The RPA reaction mixture was used at three temperatures (38-42 • C) for 30 min at the optimized primer concentration to explore the suitable reaction temperature, and the reaction time was chosen based on the previous experiments of our research team [30]. The detection result showed that the suitable reaction temperature was 42 • C (Figure 2B).…”

“…Because the lateral flow dipstick (LFD) is highly sensitive, convenient, rapid, and does not require any equipment, it has great application prospects in the field of detection [27,28]. To date, LFDs have been used for the detection of genetically modified crops [29,30], nucleic acids [31], and viruses [32], etc. In addition, RPA products can be further detected using LFDs in only 5 min, and they do not require any special equipment.…”