AgInSe2　(AISe)　quantum　dots　(QDs)　exhibit　large　Stokes　shift,　composition-dependent　photoluminescence　(PL),　long　PL　lifetimes　and　low　toxicity,　making　them　exceptional　candidates　in　a　wide　variety　of　bioapplications.　However,　it　remains　notoriously　challenging　to　precisely　control　both　the　morphology　and　composition　to　optimize　the　PL　performance　of　AISe　QDs　via　conventional　direct　synthesis.　Herein,　we　develop　the　unique　low-temperature　(75　degrees　C)　template-based　synthesis　of　highly　efficient　near-infrared　(NIR)　luminescent　AISe　QDs　from　In2Se3　QDs　via　a　facile　cation　exchange　method.　The　brief　synthesis　AISe　QDs　process　was　as　follows:　firstly,　indium　acetate　was　dissolved　in　non-coordinating　solvent　octadecene.　Selenium　precursor　was　injected　into　the　above　mixture　at　200　degrees　C,　followed　by　nucleation　and　growth　within　a　few　minutes.　Thereafter,　In2Se3　template　QDs　can　be　acquired,　and　the　dispersity　of　the　as-prepared　QDs　can　be　improved　by　adding　zinc.　Secondly,　silver　acetate　was　added　to　the　In2Se3:Zn2+　QDs　solution　with　stirring　for　15　min　at　75　degrees　C.　Finally,　AgInSe2:Zn2+　QDs　were　obtained.　The　proposed　method　enables　the　as-prepared　AISe　QDs　to　inherit　the　size　and　morphology　of　the　template　QDs.　The　extent　of　cation　exchange　can　be　controlled　by　rationally　manipulating　the　Ag/In　precursor　molar　ratio.　We　successfully　regulate　the　stoichiometry　of　Ag/In　ratio　from　0.26　to　1.09.　As　a　result,　highly　efficient　luminescence　of　AISe　QDs　with　the　maximum　absolute　quantum　yield　of　42.5%　has　been　achieved,　which　is　higher　than　that　of　the　AISe　counterparts　synthesized　via　the　direct　method.　Moreover,　we　survey　the　luminescence　mechanism　of　AISe　QDs　by　means　of　the　steady-state,　transient　and　temperature-dependent　spectroscopies.　AISe　nanoprobes　were　prepared　by　coating　the　hydrophobic　QDs　with　a　layer　of　1,2-distearoyl-sn-glycero-3-phosphoethanol-amine-N-[biotin(polyethyleneglycol)-2000]　(DSPE-PEG-Biotin)　phospholipids　through　hydrophobic　interaction.　By　virtue　of　the　excellent　biocompatibility　and　intense　NIR　emission,　we　exemplify　the　application　of　AISe　nanoprobes　in　the　targeted　cancer　cell　imaging,　thus　revealing　their　promising　bioapplications　including　disease　diagnosis　and　imaging-guided　surgery.