Laser-induced　fluorescence　(LIF)　is　one　of　the　most　sensitive　techniques　for　detection.　As　for　the　LIF　with　UV　excitation,　replacing　UV　laser　with　UV　LED　(i.e.,　UV　LED-IF)　has　advantages　of　long　life　time　and　low　cost.　However,　for　LED-IF,　the　background　signal　(noise)　would　be　much　higher,　due　to　the　poor　beam　quality　of　LED.　Here,　an　axial-excitation　UV　LED-IF　with　short　metal　capillary　(MC)　and　black　sealing　(i.e.,　MC-LED-IF)　was　proposed　for　noninvasive　detection　of　human　saliva　glucose　(HSG).　The　SNR　was　improved　3.1-fold　by　employing　the　black　sealing,　due　to　the　effective　suppression　of　the　background　signal,　which　mainly　results　from　light　leakage.　Moreover,　the　transmission　loss　of　UV　LED　light　in　MC　and　saliva-filled　MC　was　investigated,　and　an　optimal　MC　length　of　only　4　cm　was　obtained.　By　using　the　MC-LED-IF,　a　detection　limit　of　concentration　(DLC)　of　$2.4　\mu　\text{M}$　was　realized　for　detecting　HSG　via　conventional　3-(4-hydroxyphenyl)-propionic　acid　(HPPA)　reagent　with　good　selectivity　and　reliability.　The　MC-LED-IF　features　low　cost　and　compact　(　$11\times　4\times　$　4　cm),　which　is　suitable　for　personal　use.　©　2001-2012　IEEE.