Simultaneous and ultra-sensitive detection of Cu and Mg in wine and beer based on dual DNA tweezers and entropy-driven three-dimensional DNA nanomachine.

Simultaneous and ultra-sensitive detection strategy of Cu and Mg in wine and beer was developed based on dual DNA tweezers and entropy-driven three-dimensional DNA nanomachine. The dual DNAzyme can simultaneously respond to two kinds of metal ions and cause two kinds of "turn-on" fluorescent signals. The working principle of this strategy was indirectly proven. In addition, some key experimental parameters were also optimized. Under the optimum conditions, the limit of detection was 10 pM for Cu and 2 nM for Mg respectively which was significantly improved by entropy driven amplification. This strategy also showed good selectivity and specificity. It was successfully used to detect of Cu and Mg in wine and beer with 5.26% to 9.12% of relative standard deviation and 90.4% to 110.5% of recoveries.