Rhodamine hydrazone derivatives as Hg2+ selective fluorescent and colorimetric chemosensors and their applications to bioimaging and microfluidic system

• Published in: Analyst (London) Vol. 136; no. 7; pp. 1339 - 1343
• Main Authors: HA NA KIM, NAM, Seong-Won, SWAMY, K. M. K, YAN JIN, XIAOQIANG CHEN, KIM, Yonugmee, KIM, Sung-Jin, PARK, Sungsu, YOON, Juyoung
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 07.04.2011
• Subjects: Analytical chemistry; Animals; Caenorhabditis elegans - chemistry; Chemistry; Colorimetry - methods; Crystallography, X-Ray; Exact sciences and technology; Fluorescent Dyes - chemistry; General, instrumentation; Mercury - analysis; Microfluidic Analytical Techniques - methods; Molecular Conformation; Molecular Imaging - methods; Peptides, Cyclic - chemical synthesis; Peptides, Cyclic - chemistry; Rhodamines - chemistry; Spectrometric and optical methods; Fluid mechanics; Rhodamine; Visualization; Thiol; Scanning; Sample; Confocal microscopy; Colorimetry; Concentration; Chemical sensor; Caenorhabditis elegans; Carboxylic acid; Detection limit; Laser; Helmintha; Nemathelminthia; Hydrazone; Invertebrata; Nematoda; Application; Microfluidics
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c0an00804d

In this paper, we report new rhodamine hydrazone derivatives bearing thiol and carboxylic acid groups as selective fluorescent and colorimetric chemosensors for Hg(2+). The ring-opening process of spirolactam enables the large fluorescent enhancement and colorimetric change upon the addition of Hg(2+). The sample containing Hg(2+) was mixed with one of the chemosensors in a microchannel where the sensor was examined using confocal laser scanning microscopy. A plot of the fluorescent intensities of both chemosensors versus the log concentration of Hg(2+) exhibited a linear response (r(2)=0.95) in the range of 1 nM-1 μM, and the detection limits were 1 nM and 4.2 nM, respectively. Both chemosensors also enable the visualization of Hg(2+) accumulated in the nematode Caenorhabditis elegans previously exposed to nanomolar concentrations of Hg(2+).