Resonance Scattering Effect of Dopamine Product Particle and Its Application to Polyphenoloxidase Activity Assay

Abstract

In pH 7.2 Na 2 HPO 4 -NaH 2 PO 4 buffer solution, polyphenoloxidase (PPO) could catalyze the oxidization of dopamine (DA) to form polymer particles in dark-red color, which exhibited a strong resonance scattering (RS) peak at 780 nm. In the chosen conditions, as the PPO activity increased, the RS intensity at 780 nm increased linearly. The increased RS intensity (∆I 780 nm ) was linear to the PPO activity in the range of 0.10-6.0 U•mL PPO. The proposed method was applied to detecting PPO activity in potato sample with satisfactory results.

New Method for Accurate Determination of Polyphenol Oxidase Activity Based on Reduction in SERS Intensity of Catechol

“…When the reaction medium without PPO solution was used, Δ I /Δ t was 114.24 ± 46.60; therefore, the LOD of the present method was determined as 224.65 U/L (LOD = 3S/K, K = 0.6223, S = 46.60). Compared with the linear range of 1000–10 000 U/L and LOD of 500 U/L for colorimetric assay reported by Jiang et al, the linear range in the current study was wider, being 500–50 000 U/L, and LOD was lower, being 224.65 U/L.…”

“…As PPOs play a vital role in catalyzing enzymatic reactions in the food industry, many studies dealing with the determination of PPO activity and its changes during storage and processing have been presented . Colorimetric assay is the most traditional and common method used for analyzing PPO activity. − In addition, the determination of PPO activity by optical, amperometric, and immune biosensors ,, and its rapid prediction by hyperspectral imaging and other methods have also been reported. − Among these methods, although colorimetric assay is the simplest one, its test result is labile to interference due to the instability of the reaction product. Biosensor-based methods are accurate and sensitive, but the measurement procedure is generally complex, time-consuming, and tedious, making such methods unsuitable for rapid determination of the PPO activity.…”

Resonance light scattering determination of trace bisphenol A with signal amplification by aptamer–nanogold catalysis

“…Resonance light scattering (RLS) is a simple and sensitive technique used to analyze trace metal ions, protein and nucleic acids, based on associated, chelated, redox, metal ion and enzyme catalytic particle reactions . However, selectivity was not high in most of them, and complicated samples can not be analyzed.…”

A Simple and Sensitive Label‐free Immunoassay for Factor B Using Resonance Scattering Spectral Detection

“…[2,3] Thus, developing simple and specific immunoassays for factor B with sufficient sensitivity and accuracy is of considerable interests for clinical chemistry. [6][7][8][9][10][11][12] Based on highly sensitive and selective immune and aptamer reactions with nanogold-labeling, some nanogold-labeled RSS methods have been proposed for antigens and targets. [4] Based on a novel immobilization strategy combining cysteamine self-assembled monolayer and chitosan/alginate adsorptionprocedure, a piezoelectric immunosensor has been de-veloped for the determination of factor B in human serum.…”