First　principles　calculations　are　carried　out　to　investigate　the　reactivities　of　pure　monolayer　MoS2　nanosheet　doped　with　non-metal　elements　X　(X　=　B,　P,　Cl)　in　the　presence　of　NO.　All　doped　systems　exhibit　strong　effects　on　NO,　especially　for　the　B-　and　P-doped　MoS2　cases,　whereas　the　pure　MoS2　shows　weak　physisorption　of　NO.　To　fully　explore　the　mechanism　of　strengthening　interactions　between　the　substrate　and　NO,　we　discuss　the　changes　in　the　electronic　structure,　which　determines　the　electrical　conductivity.　We　suggest　that　P-doped　MoS2　is　a　suitable　candidate　for　sensing　NO　polluting　gas,　while　the　chemisorption　of　NO　on　B-doped　MoS2　is　so　strong　that　NO　desorption　is　difficult.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.