The　design　and　development　of　contrast　agents　for　magnetic　resonance　imaging　(MRI)　with　improved　chemical　stability　and　higher　contrasting　capability　for　clinical　translation　compared　to　conventional　contrast　agents　are　still　of　great　interest.　In　this　study,　a　facile　and　universal　approach　was　explored　for　controllable　functionalization　of　red-emissive　carbon　nanodots　(RCNDs)　with　diethylenetriaminepentaacetic　anhydride　(DTPA)　for　chelation　of　gadolinium.　A　series　of　accurate　characterizations　were　used　to　control　each　step　of　the　synthesis.　The　functionalization　did　not　alter　the　band　gap　of　the　carbon　nanodots,　preserving　their　inherent　far-red　fluorescence.　The　as-prepared　RCND-DTPA-Gd　displayed　a　high　colloidal　stability　with　negligible　Gd　leakage.　The　nanodots　also　showed　a　better　magnetic　resonance　relaxivity　than　commercial　MRI　agents.　RCND-DTPA-Gd　had　good　biocompatibility　in　vivo　even　at　high　doses.　The　systemically　injected　RCND-DTPA-Gd　were　found　to　be　efficiently　excreted　through　the　renal　route,　a　feature　that　further　minimizes　the　potential　toxicity　risks.　All　these　properties　suggest　that　carbon　nanodots　can　be　well　designed　as　efficient　carriers　of　Gd,　resulting　in　potential　clinical　tools　as　dual　MRI/fluorescence　functional　probes　for　imaging　applications.　The　approach　described　here　could　pave　the　pathway　to　a　flexible　strategy　for　the　controllable　functionalization　of　small-sized　nanoparticles　including　carbon　dots,　rendering　them　more　versatile.　This　work　is　expected　to　promote　the　future　translation　of　carbon　nanodots　into　clinical　trials.　©　2021　American　Chemical　Society.　All　rights　reserved.