Colorimetric Differentiation of Flavonoids Based on Effective Reactivation of Acetylcholinesterase Induced by Different Affnities between Flavonoids and Metal Ions

Abstract

Flavonoids are closely related to human health, and the distinguishiment of flavonoids is an important but difficult issue. We herein unveil a novel colorimetric sensor array for the rapid identification of 7 flavonoids (e.g., gallocatechin (GC), morin hydrate (MH), puerarin (Pu), epigallocatechin gallate (EGCG), catechin (C), rac Naringenin (rN), and Flavone (Fla)) for the first time. The colorimetric performances of gold nanoparticles (AuNPs) are characteristically correlated with thiocholine, which is issued from the enzymatic hydrolysis of acetylcholine (AcCh). Therefore, as a proof-of-concept design, three sensors (Cu2+/acetylcholinesterase (AcChE)/AcCh/AuNPs, Zn2+/AcChE/AcCh/AuNPs, and Mn2+/AcChE/AcCh/AuNPs) were constructed to form our sensor array. The distinct affinities between flavonoids and metal ions would cause varying degrees of effective reactivation of AcChE, leading to unique colorimetric response patterns upon being challenged with the seven flavonoids for their pattern recognition, enabling an excellent identification of the seven flavonoids at a concentration of 20 nM and different concentrations of individual flavonoids, as well as mixtures of them.

CdTe QD-based inhibition and reactivation assay of acetylcholinesterase for the detection of organophosphorus pesticides

“…4 To combat this, AChE reactivators have been developed to remove the offending AChE inhibitors, restoring acetylcholine levels to normal. 5,6 It is really challenging to design a nanoprobe for monitoring AChE activity in the presence of reversible (carbamate, acridine) and irreversible (organophosphorus) inhibitors. The probe reported thus far can determine the inhibition 7 of AChE, and is limited to monitoring percentage reactivation of organophosphorusinhibited enzyme.…”

A Critical Factor for Quantifying Proteins in Unmodified Gold Nanoparticles-Based Aptasensing: The Effect of pH

“…Gold nanoparticle (AuNP)-based colorimetric biosensors have been widely used in diagnostics [1,2], environmental monitoring [3,4], and food analysis [5,6]. Among these, an unmodified AuNPs-based aptasensing (uGA) assay [7,8], which incorporated DNA aptamer (in vitro selected oligonucleotides with specific target binding abilities) [9,10] and unmodified AuNPs in the design of colorimetric biosensors, arouse considerable attention due to their high specificity, ease-of-use, and label-free properties.…”

Epigallocatechin gallate triggers apoptosis by suppressing de novo lipogenesis in colorectal carcinoma cells

“…Anti-inflammatory, antioxidant and chemopreventive qualities are the most recognized effects of the catechin group [21]. Flavonoids are the most prevalent polyphenolic secondary compounds derived from plant metabolites found in plant-based food such as fruits, flowers, vegetables, grains and wine [22]. Flavonoids are composed of flavones, flavonols (3-hydroxyflavone), flavanols, isoflavones and anthocyanidins, which all have the same flavan backbone structure [23,24].…”