The　functionalization　of　noble　metals　is　an　effective　approach　to　lowering　the　sensing　temperature　and　improving　the　sensitivity　of　metal　oxide　semiconductor　(MOS)-based　gas　sensors.　However,　there　is　a　dearth　of　comparative　analyses　regarding　the　differences　in　sensitization　mechanisms　between　the　two　functionalization　modes　of　noble　metal　loading　and　doping.　In　this　investigation,　we　synthesized　Pt-doped　CuO　gas-sensing　materials　using　a　one-pot　hydrothermal　method.　And　for　Pt-loaded　CuO,　Pt　was　deposited　on　the　synthesized　pristine　CuO　surface　by　using　a　dipping　method.　We　found　that　both　functionalization　methods　can　considerably　enhance　the　response　and　selectivity　of　CuO　toward　NO2　at　low　temperatures.　However,　we　observed　that　CuO　with　Pt　loading　had　superior　sensing　performance　at　25　degrees　C,　while　CuO　with　Pt　doping　showed　more　substantial　response　changes　with　an　increase　in　the　operating　temperature.　This　is　mainly　due　to　the　different　dominant　roles　of　electron　sensitization　and　chemical　sensitization　resulting　from　the　different　forms　of　Pt　present　in　different　functionalization　modes.　For　Pt　doping,　electron　sensitization　is　stronger,　and　for　Pt　loading,　chemical　sensitization　is　stronger.　The　results　of　this　study　present　innovative　ideas　for　understanding　the　optimization　of　noble　metal　functionalization　for　the　gas-sensing　performance　of　metal　oxide　semiconductors.