title: Multidimensional optical sensing platform for detection of heparin and reversible molecular logic gate operation based on the phloxine B/polyethyleneimine system.
abstract: 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.
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ling
authors.forename: Zhong Feng
authors.initials: ZF
authors.lastname: Gao
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhou
authors.forename: Nian Bing
authors.initials: NB
authors.lastname: Li
authors.forename: Hong Qun
authors.initials: HQ
authors.lastname: Luo
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D010697:Eosine I Bluish / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006493:Heparin / Q000032:analysis* / Q000302:isolation & purification; D006801:Humans; D057230:Limit of Detection; D061848:Optical Imaging / Q000379:methods*; D011094:Polyethyleneimine / Q000737:chemistry*; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D011094:Polyethyleneimine; D006493:Heparin; D010697:Eosine I Bluish