I don't know the technical details of MinION. Coupling good capture with amplification and detection is required. When working on dna detection you use somethi

I don't know the technical details of MinION. Coupling good capture with amplification and detection is required. When working on dna detection you use something like pcr for signal amplification. But surface detection can in some cases be more sensitive, since you generally have a lot more surface fragments available than you have dna or rna. Especially since many viral diseases form have huge ratios of surface fragments per every well formed infectious viral particle. Generally: a sequencer by itself doesn't have the sensitivity required. For example, for norovirus we're talking about detecting a few virus particles per cubic meter of air. You need insanely sensitive detection tech to be able to do that.