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.

Polyethyleneimine as a novel desorbent for anionic organic dyes on layered double hydroxide surface

“…The performances of PEI depend on the pH values of the solutions [15]. Therefore, the effect of different pH values in a wide range of 4.0-13.0 on desorption capacity of PEI toward methyl orange was investigated systematically to clarify the mechanism of PEI-enhanced desorption.…”

“…Polyethyleneimine (PEI) is a cationic water-soluble polymer with a large number of primary, secondary and tertiary amino groups (Fig. S1a) [15,16]. The protonation of amine groups on the macromolecular chains of PEI leads to its positive charges, facilitating the electrostatic attraction toward negatively charged compounds [17].…”

A supramolecular host–guest complex for heparin binding and sensing

“…Many colorimetric [10][11][12][13][14] and fluorescent [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] heparin sensors with different functionalities and varying structures from small molecules 11,14,[18][19][20][21][22] and host-guest complexes 16,24 to synthetic polymers 12,[27][28][29] and peptides 31,32 have been developed. For instance, a boronic acid based receptor utilizing preorganization of the structure provided a colorimetric heparin indication system capable in selective heparin binding.…”

A Label-free Resonance Rayleigh Scattering Sensor for Detection of Thrombin Based on Aptamer Recognizing

“…Because of the simplicity and high sensitivity, resonance Rayleigh scattering (RRS) has been widely utilized in analytical applications, such as for the detection of biological molecules, metal ions, surfactant, and so on. [24][25][26][27][28][29][30] Herein, we introduced the label-free TBA as a molecular recognition probe for facile, highly sensitive, and selective detection of TB by resonance Rayleigh scattering method. The characteristics of RRS spectra for the interaction between TBA and TB were investigated.…”