Abstract
A novel fluorometric strategy for the simultaneous identification of SARS-CoV-2 and SARS-CoV was successfully established based on a hybridization-induced signal on-off-on mechanism. Here, one part of the probe (P1) of SARS-CoV-2 (P = P1/P2) is partially related to SARS-CoV, while the other part (P2) is completely irrelevant to SARS-CoV. They as smart gatekeepers were anchored on NH(2)-MIL-88(Fe) (MOF@P1/P2) to turn off its catalytic performance. Only the specific SARS-CoV-2 genetic target can strongly restore the peroxidase-like activity of MOF@P1/P2. In the presence of o-phenylenediamine, SARS-CoV-2 can be efficiently detected with high sensitivity, accuracy, and reliability. This strategy demonstrated excellent analytical characteristics with a linear range (10(-9) M ∼ 10(-6) M) under the limit of detection of 0.11 nM not only in buffer but also in 10 % serum, which partly shows its practicability. Most importantly, with the help of the auxiliary test of MOF@P1 and MOF@P2, SARS-CoV-2 and SARS-CoV can be efficiently quantified and distinguished. This novel strategy has provided a breakthrough in the development of such identification. In the whole process, only a simple one-step experiment was involved. This circumvents the trouble of pretreatment experiments in traditional methods, including complex enzymatic mixtures, specialized experimental equipment, many primers optimization as well as reverse transcriptase. Additionally, this novel strategy is rapid, low-cost, and easy-to-use tools.