A Dual Sensor Probe for the Sequential Detection of Copper(II) and Lactic Acid

<p>Herein, we report<b> </b>a novel fluorescent probe for the sequential detection of Copper II (Cu<sup>2+</sup>) and lactic acid. The probe based on acyl-thiourea derivative, N-((6-methoxypyridin-2-yl)carbamothioyl)benzamide (<b>1</b>) was synthesized, and its application as dual sensor for Cu<sup>2+</sup> and lactic acid is reported. The dual detection by the probe is possible since <b>1 </b>formed complex with Cu<sup>2+ </sup>and yielded yellow solution which disappeared after the addition of lactic acid. The probe exhibits yellow fluorescence with Cu<sup>2+ </sup>and LOD of Cu<sup>2+</sup> with fluorescence is as low as 0.1ppm. The fluorescence is quenched after the addition of lactic acid and LOD of fluorescence quenching by lactate is as low as 1 ppm. Further, structural modification in the probe <b>1</b> suggest crucial role of both pyridine and acyl-thiourea moiety in the binding of Cu<sup>2+</sup>. Interestingly, <b>1</b> also assembles to fluorescent fibers which show tunable emission properties. These fibers are broken in the presence of Cu<sup>2+</sup> and regenerated in the presence of lactic acid. Hence, disaggregation at molecular level might play a crucial role in causing yellow fluorescence in the presence of Cu<sup>2+</sup>. To, the best of our knowledge, this is the first report wherein a dual sensor for Cu<sup>2+</sup> and lactate ion is synthesized and it may in all possibilities pave the way for diagnosis of Cu<sup>2+</sup> associated disorders like Wilson’s disease and in the detection of elevated lactate levels which are associated with wide range of pathologies like mitochondrial diseases, cerebral ischemia and cancer.<b></b></p>