Intramolecular Enhancement of a Zirconium-Based Metal-Organic Framework for Coordination-Induced Electrochemiluminescence Bleomycin Analysis

It is significantly vital to develop a convenient assaymethodin clinical treatment due to an atypically low abundance (& SIM;5 & mu;M) of bleomycin (BLM) used in clinics. Herein, an electrochemiluminescence(ECL) biosensor using a zirconium-based metal-organic frameworks(Zr-MOFs) as an intramolecular coordination-induced electrochemiluminescence(CIECL) emitter was proposed for sensitive detection of BLM. Zr-MOFswere synthesized using Zr(IV) as metal ions and 4,4 & PRIME;,4 & DPRIME;-nitrilotribenzoicacid (H3NTB) as ligands for the first time. The H3NTB ligand not only acts as coordination units bonding with Zr(IV)but functions as a coreactant to enhance ECL efficiency rooted inits tertiary nitrogen atoms. Specifically, a long guanine-rich (G-rich)single-stranded DNA (ssDNA) was released by the target-BLM-controlledDNA machine that could perform & pi;-& pi; stacking withanother G-quadruplex, ssDNA-rhodamine B (S-RB), by shearing DNA'sfixed sites 5 & PRIME;-GC-3 & PRIME; and the auxiliary role of exonucleaseIII (Exo III). Finally, due to the quenching effect of rhodamine B,a negative correlation trend was obtained between ECL intensity andBLM concentration in the range from 5.0 nM to 50 & mu;M and thelimit of detection was 0.50 nM. We believe that it is a promisingapproach to guide the preparation of CIECL-based functional materialsand establishment of analytical methods.

Automated summary

Developing a convenient assay method is crucial for clinical treatment due to the low abundance of bleomycin. This study proposes an electrochemiluminescence biosensor using zirconium-based metal-organic frameworks for sensitive detection of bleomycin. The use of a long guanine-rich single-stranded DNA and the auxiliary role of exonuclease III enhance the electrochemiluminescence efficiency. The negative correlation between electrochemiluminescence intensity and bleomycin concentration enables the accurate detection of bleomycin in the range from 5.0 nM to 50 μM, with a limit of detection of 0.50 nM.