Multidimensional Optical Sensing Platform for Detection of Heparin and Reversible Molecular Logic Gate Operation Based on the Phloxine B/Polyethyleneimine System

• Published in: Analytical chemistry (Washington) 2015-02, Vol.87 (3), p.1575-1581
• Main Authors: Ling, Yu, Gao, Zhong Feng, Zhou, Qian, Li, Nian Bing, Luo, Hong Qun
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Biosensing Techniques - methods; Desorption; Detection; Electrostatics; Eosine I Bluish - chemistry; Fluorescence; Fluorescent Dyes - chemistry; Gates; Heparin - analysis; Heparin - isolation & purification; Heparins; Humans; Limit of Detection; Logic; Molecules; Optical Imaging - methods; Polyetherimides; Polyethyleneimine; Polyethyleneimine - chemistry; Scattering, Radiation; Spectrometry, Fluorescence; Wavelengths
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac504023b

A multidimensional optical sensing platform which combines the advantages of resonance Rayleigh scattering (RRS), fluorescence, and colorimetry has been designed for detection of heparin. Phloxine B, a fluorescein derivative showing the special RRS spectrum in the long wavelength region, was selected to develop an easy-to-get system which can achieve switch-on sensing to obtain high sensitivity. The noise level of RRS in the long wavelength region is much weaker, and the reproducibility is much better; in this way, the sensitivity and selectivity can be improved. In the absence of heparin, the phloxine B and polyethyleneimine (PEI) form a complex through electrostatic interaction. Thus, the RRS signal at 554 nm is low; the phloxine B fluorescence is quenched, and the absorption signal is low. In the presence of heparin, competitive binding occurred between phloxine B and heparin toward PEI; then, phloxine B is gradually released from the phloxine B/PEI complex, causing obvious enhancement of the RRS, fluorescence, and absorption signals. Besides, the desorption of phloxine B is less effective for the heparin analogues, such as hyaluronic acid and chondroitin sulfate. In addition, the system presents a low detection limit of heparin to 5.0 × 10–4 U mL–1 and can also be applied to the detection of heparin in heparin sodium injection and 50% human serum samples with satisfactory results. Finally, the potential application of this method in reversible on–off molecular logic gate fabrication was discussed using the triple-channel optical signals as outputs.