Simultaneous detection of Dengue and Zika virus RNA sequences with a three-dimensional Cu-based zwitterionic metal-organic framework, comparison of single and synchronous fluorescence analysis

A water soluble and stable metal-organic framework (MOF) [Cu(Dcbcp)(bpe)](n) (1, Dcbcp = N-(3,5-dicarboxylbenzyl)-(3-carboxyl) pyridinium, bpe = 1,2-bis(4-pyridyl) ethylene) was synthesized. MOF 1 possesses a three-dimensional open framework with large pores and has a high affinity toward carboxyfluorescein (FAM) or 5(6)-carboxyrhodamine, triethylammonium salt (ROX)-tagged single-stranded probe DNA (P-DNA) through pi stacking, electrostatic interactions, thus quenching the fluorescence of tag. The two formed P-DNA@1 systems can be applied for simultaneous detection of Dengue virus (DENV) and Zika virus (ZIKV) RNA sequences, which is attributed to the different affinities of MOF 1 with P-DNA and the double-stranded DNA/RNA formed upon recognition. With the same detection time of 36 min and 2 min, the detection limits are 332 and 192 pM with the single detection method, 184 and 121 pM with synchronous fluorescence detection method. Both assays are highly specific and not interfered by other mismatched RNA sequences, even down to single-base mismatched RNA sequences. There was no cross-reaction between the two probes for synchronous detection. Comparing these two methods, synchronous fluorescence analysis improves the detection efficiency by saving the time and increasing the detection limits, which may attribute to its avoiding the interference of Raleigh light scattering signal to the fluorescence signal. (C) 2017 Published by Elsevier B.V.