Mimetic biosensors composed by layer-by-layer films of phospholipid, phthalocyanine and silver nanoparticles to polyphenol detection

Abstract

Highly selective and sensitive modified electrodes have been the focus of many studies in sensing applications. Gene or enzymatic biosensors are greatly effective in this context, but they are often fragile and expensive. An alternative to these systems is the use of mimetic systems such as artificial enzyme immobilized in a matrix formed by thin films, for which the electrostatic layer-by-layer (LbL) technique has been widely applied. Here, the formation of bilayers or trilayers combining a cationic electrolyte (poly(allylamine) hydrochlorate, PAH), an anionic metallic complex (iron tetrasulfonated phthalocyanine, FeTsPc), an anionic phospholipid 1,2-dipalmitoyl-sn-3-glycero-(phosphor-rac-(1-glycerol), DPPG) and silver nanoparticles (AgNPs) arranged as (PAH/FeTsPc + DPPG)n and (PAH/FeTsPc + DPPG/AgNP)n was structurally and morphologically characterized. The electrostatic interaction of PAH, FeTsPc, and DPPG molecules were identified as the driven forces that allow the LbL film growth. The incorporation of AgNPs in the LbL films makes possible to active the surface enhanced resonant Raman scattering (SERRS) effect. The LbL films were evaluated as a sensor to catechol by cyclic voltammetry and impedance spectroscopy. The presence of AgNPs enhances the electrocatalytic activity of FeTsPc in the film to catechol oxidation. The (PAH/FeTsPc + DPPG/AgNP) 5 LbL film presented a linear concentration range for catechol detection from 2 up to 100 M, with a limit of detection of 0.87 M. The distinction of catechol concentrations as well as discrimination among catechol, gallic and vanillic acid aqueous solutions was efficiently performed by principal component analysis (PCA) from impedance spectroscopy measurements. The LbL films here evaluated showed suitable properties to be applied as mimetic biosensors. The sensor was applied to polyphenol determination in green tea samples by standard addition showing high selectivity to catechol compared with results from Folin-Ciocalteu method.

Simultaneous Determination of Different Phenolic Compounds Using Electrochemical Biosensor and Multivariate Calibration

“…15 There is a wide variety of metallic nanoparticles, which can be found in the literature, as supports for biosensor construction, including gold, 16 platinum, 17 bismuth 18 and silver 19 as well as zinc 11 and manganese oxides. 20 However, the use of magnetic nanoparticles based on iron oxides has the benefit of producing adsorptive materials that are responsive to magnetic field, which can be re-dispersed if magnetism is removed, thus offering the advantage for magnetic separation.…”

A Comprehensive Insight on the Health Benefits and Phytoconstituents of Camellia sinensis and Recent Approaches for Its Quality Control

“…Tea quality assessment using an electro-analytical technique based on a flow injection analysis coupled with dual electrochemical detector system was used for the highly selective simultaneous detection of polyphenolic functional groups in catechins, especially in EGCG [284]. A modified electrode with high selectivity to catechol can be used to determine polyphenol [285], while gold nanoparticles decorated on porous aromatic framework can be used to directly determine quercetin in green tea samples [286].…”

Discrimination of Milks with a Multisensor System Based on Layer-by-Layer Films

“…Moreover, hybrid structures can be developed, combining different materials in the layered structure that can improve the final sensing properties. Finally, it is an advantageous method to immobilize enzymes in a biomimetic environment [ 11 , 12 , 13 , 14 , 15 ].…”

“…Phthalocyanines have been widely used as sensing materials in electrochemical sensors due to their chemical reactivity, their excellent electrocatalytic properties, as well as the capability to form LbL nanostructured films [ 11 , 16 ]. The LbL technique can be used to combine the water soluble anionic metal tetrasulfonated phthalocyanines (MPc S ) with other cationic materials, to obtain hybrid layers with improved catalytic properties [ 17 ].…”