(a) LAMP experiments demonstrated primer specificity. NC: control, PC: SARS-CoV-2 positive mRNA was added. (b) Optimization of the ssDNA probe concentration. A: Blank control; B: Experimental group 4. Add NEBuffer2.1, Cas12a, gRNA, 10 μL of ssDNA, 10 μL of LAMP product; C: Experimental group 3. Add NEBuffer2.1, gRNA, 5 μL of ssDNA, 10 μL of LAMP product; D: Negative control group. Add NEBuffer2.1, Cas12a, gRNA, ssDNA, and LAMP products of SARS-CoV-2 negative samples; E: Experimental group 1. Add NEBuffer2.1, Cas12a, gRNA, 10 μL of LAMP product; F: Experimental group 2. Add NEBuffer2. 1, Cas12a, gRNA, 1 μL of ssDNA,10 μL of LAMP product; G: Experimental group 5. Add NEBuffer2.1, Cas12a, gRNA, 15 μL of ssDNA, 10 μL of LAMP product; H:Experimental group 6. Add NEBuffer2.1, Cas12a, 10 μL of ssDNA, 10 μL of LAMP product. (c) Quantitative verification of RT-LAMP-CRISPR-Cas12a system. NC: Negative control group. Add NEBuffer2.1, Cas12a, gRNA, ssDNA, and LAMP products of SARS-CoV-2 negative samples; E1: Experimental group 1. Add NEBuffer2.1, Cas12a, gRNA, ssDNA; E2: Experimental group 2. Add NEBuffer2.1, Cas12a, gRNA, 10 μL of LAMP product; E3: Experimental group 3. Add NEBuffer2.1, gRNA, ssDNA, 10 μL of LAMP product; E4: Experimental group 4. Add NEBuffer2.1, Cas12a, gRNA, ssDNA, 10 μL of LAMP product. ^****P<0.000 1. (d) Observing the effects of varying ssDNA concentrations under UV irradiation. NC: Negative control group. Add NEBuffer2.1, Cas12a, gRNA, ssDNA, and LAMP products of SARS-CoV-2 negative samples; E1: Experimental group 1. Add NEBuffer2.1, Cas12a, gRNA, 10 μL of LAMP product; E2: Experimental group 2. Add NEBuffer2. 1, Cas12a, gRNA, 1 μL of ssDNA,10 μL of LAMP product; E3: Experimental group 3. Add NEBuffer2.1, gRNA, 5 μL of ssDNA, 10 μL of LAMP product; E4: Experimental group 4. Add NEBuffer2.1, Cas12a, gRNA, 10 μL of ssDNA, 10 μL of LAMP product; E5: Experimental group 5. Add NEBuffer2.1, Cas12a, gRNA, 15 μL of ssDNA, 10 μL of LAMP product