A　simple　and　novel　electrochemical　immunoassay　based　on　MXene　(Ti3C2)−Au　nanoparticles　(AuNPs)　was　designed　for　sensitive　screening　of　a　disease-related　biomarker,　prostate-specific　antigen　(PSA),　by　using　dopamine-loaded　liposomes　(DLL)　for　signal　amplification.　The　system　involves　two　parts,　namely,　sandwich-type　immunoreaction　to　capture　DLL　and　electrochemical　measurement　of　dopamine.　The　target　PSA　can　cause　a　specific　antigen-antibody　reaction　and　DLL　are　enriched　in　the　enzyme-labeled　pores.　After　Triton　X-100　is　injected　into　the　detection　cell,　the　carried　DLL　was　quickly　cracked　to　release　dopamine　wrapped　in　the　cavity.　A　nanocomposite　consisting　of　MXene　(Ti3C2)　support　to　immobilize　Au　nanoparticles　(Ti3C2−Au)　was　utilized　to　modify　a　glassy　carbon　electrode,　which　gives　a　strongly　enhanced　differential　pulse　voltammetric　(DPV)　signals　for　dopamine.　In　this　case,　the　change　of　DPV　signal　depends　on　the　amount　of　dopamine　released　by　liposomes,　which　is　further　positively　correlated　with　the　concentration　of　the　analyte　PSA.　Combining　the　of　MXene　(Ti3C2)−AuNPs　nanomaterials　(large　specific　surface　area,　excellent　electrical　conductivity,　and　good　electrocatalytic　properties)　with　the　liposome　signal　amplification　strategy,　the　electrochemical　immunoassay　exhibited　excellent　performance　toward　PSA　determination　with　a　broad　linear　range　of　1　pg/mL　to　50　ng/mL　and　limit　of　detection　down　to　0.31　pg/mL　(S/N=3)　under　the　optimized　testing　conditions.　High　specificity　for　PSA　over　other　disease-related　biomarkers　and　acceptable　nanocomposite/electrode　stability　were　acquired.　The　excellent　analytical　performance　shows　that　the　current　strategy　provides　an　effective　detection　platform　for　clinical　sample　analysis.　©　2022　Wiley-VCH　GmbH.