Developing a unique metal-organic framework-{[Cd(abtz)2(NCS)]·(ClO4)}n (abtz = 1-(4-aminobenzyl)-1,2,4-triazole) as fluorescent probe for highly selective and sensitive detection of ascorbic acid in biological liquid

Abstract

Nowadays metal-organic frameworks (MOFs) have aroused great interest because of their fascinating tunable structures and unusual functional properties. In the recent years, MOFs have been used as new sensing materials to effectively detect cations, anions and nitroaromatic complexes due to their high selectivity and good sensitivity. In this work, we explored a unique fluorescent metal-organic framework {[Cd(abtz)2(NCS)]·(ClO4)}n (MOF-Cd-abtz; abtz=1-(4-aminobenzyl)-1,2,4-triazole) for highly selective and sensitive detection of ascorbic acid in biological liquid (such as human urine and serum samples). Because both the fluorescent material MOF-Cd-abtz and ascorbic acid can absorb the excitation light at 250nm, thereby ascorbic acid can quantitatively quench fluorescent signals of MOF-Cd-abtz in biological liquid. This MOF-Cd-abtz based fluorescent method exhibits good liner response to ascorbic acid in the range of 0.1–140μM. The relative standard deviation (RSD) for three times replicate detections of 25μM ascorbic acid was 0.94%, and the detection limit was 75nM (S/N=3). The developed method can be applied for the determination of ascorbic acid in human urine and serum samples with quantitative spike recoveries from 93% to 103%.