Development of enzyme/titanate nanosheet complex coated with molecularly imprinted polydopamine for colorimetric quercetin assay

Abstract

A novel hybrid material, which is an enzyme/inorganic nanosheet complex coated by molecularly imprinted polymer (MIP), was developed, and applied to colorimetric quercetin assay. First, an enzyme/inorganic nanosheet complex was prepared from horseradish peroxidase (HRP) enzyme and titanate nanosheet (TiOx), using electrostatic interactions between them in acetate buffer. In the next place, dopamine self-polymerization was performed in the presence of HRP/TiOx complex with quercetin as a template, to prepare MIP membrane onto the HRP/TiOx complex. After washing process, a new hybrid material, MIP-coated HRP/TiOx complex (MIP-HT) was obtained. MIP-HT adsorbed quercetin efficiently, compared with NIP-HT that is an HRP/TiOx complex coated with non-imprinted polydopamine. MIP-HT showed enzymatic activity for an oxidation reaction of guaiacol, which is a chromogenic substrate of HRP, whereas the enzymatic activity of NIP-HT was significantly suppressed. The amount of brown product, formed by the color reaction, reduced owing to the presence of quercetin in sample solution, and a good liner relationship was observed between the concentration of quercetin and the increment of absorbance at 470 nm. The investigation using several biomolecules indicates that MIP-HT has the ability to detect quercetin and its analogues with selectivity. Therefore, MIP-HT shows great promise as a new and attractive material for use in colorimetric assay of quercetin or quercetin analogues.

State‐of‐the‐art molecular imprinted colorimetric sensors and their on‐site inspecting applications

“…No color Brown [11] 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) No color Green [12] O-phenylenediamine No color Brown [13] Pyrogallol No color Yellow [14] structure produces a photonic band gap, and photons with energy inside the photonic band gap cannot enter the crystal. These PhCs only allow the light with specific frequency wavelengths to pass through and exhibit unique structural colors based on Bragg diffraction.…”

An Enhanced Photosensitive Sensor Based on ITO/MWCNTs@Polymer Composite@BiVO4 for Quercetin Detection

“…Techniques including high-performance liquid chromatography (HPLC) [5,6], HPLC-mass spectrometry/mass spectrometry (MS/MS) [7,8], fluorescent methods [9][10][11], colorimetric techniques [12,13], chemiluminescent detection [14,15], biosensors [16,17],…”

“…Each of these techniques exhibit both superiorities and deficiencies. In recent years, the use of biosensors and sensors in quercetin analysis has increased due to the disadvantages of other techniques, such as the high cost of instrumental techniques (HPLC and HPLC-MS/MS), the difficulties in the application of fluorescent and chemiluminescent techniques, and low detection limits of colorimetric techniques at ~0.0033-0.0910 mM [12,13]. Electrochemical enzyme-based sensors have been applied to a wide field of study.…”