Lanthanide/nucleotide coordination polymers: an excellent host platform for encapsulating enzymes and fluorescent nanoparticles to enhance ratiometric sensing

This work demonstrated the potential of lanthanide/nucleotide coordination polymers as a host platform for encapsulating enzymes and fluorescent nanoparticles to fabricate multifunctional composites. The self-adaptive assembly of terbium ions (Tb3+), adenosine monophosphate (AMP), glucose oxidase (GOx), and carbon dots (CDs) leads to the formation of a GOx&CDs@AMP/Tb composite with catalytic and fluorescence properties. Owing to the confinement effect, the GOx&CDs@AMP/Tb composite exhibited about 2-fold higher catalytic activity than free GOx. Meanwhile, significantly enhanced storage stability and negligible leakage of GOx were also achieved. On this basis, by considering the advantages of carboxyphenylboronic acid (CPBA) in the sensitization of Tb3+ fluorescence and specific recognition of hydrogen peroxide, a dual-emissive GOx&CDs@AMP/Tb-CPBA composite was further fabricated for the ratiometric sensing of glucose. Benefiting from the synergistic effect of GOx and CDs in the highly efficient transfer of intermediates and the elimination of environmental fluctuations, the presented ratiometric sensor not only displayed an ultrahigh sensitivity with a detection limit of 80 nM, but also allowed glucose to be easily identified by the naked eye under a UV lamp. We hope that this study will provide a new insight into the design and application of coordination polymer-based multifunctional composites.