Nonenzymatic Electrochemical Biosensor Constructed by Nanocomposites Applied to the Detection of Cold-Resistant RNA in Winter Wheat

Winter wheat, a significant food crop in China, is known for its high nutritional value; however, its yield is limited by low temperatures, which prevent safe overwintering in cold northern regions. It is, therefore, crucial to research the cold resistance of winter wheat, including the development of a new, cost-effective, swift, and sensitive immunoassay method. In this study, a label-free, efficient, and ultrasensitive electrochemical biosensor was constructed based on a glassy carbon electrode (GCE) modified with gold nanoparticles, molybdenum disulfide (MoS2) nanospheres, and cobalt hydroxide nanosheets (Au@MoS2/Co(OH)
$_{{2}}{)}$
nanocomposites, and a series of characterization studies were performed. The single-stranded complementary RNA (cRNA) probe was immobilized on it, and pairwise binding occurred after adding the target single-stranded RNA (ssRNA), and then, its detection performance was analyzed using a series of electrochemical techniques. The experimental results showed that the prepared electrochemical biosensor for cold-resistant RNA detection in winter wheat exhibited a large electroactive surface area, high conductivity, strong electron transfer, and excellent biocompatibility. It has a wide detection linear range of 0.001 nM–
$100 \mu \text{M}$
, a low detection limit of 0.18 pM (S/N = 3), and also high sensitivity, good selectivity, and stability. More importantly, it is simpler, cheaper, and faster than traditional detection methods, indicating that it may contribute to the fields of stable wheat yield and analytical detection.