A Multi-Catalytic Sensing for Hydrogen Peroxide, Glucose, and Organophosphorus Pesticides Based on Carbon Dots.

Ping Li,Jiang-Shan Shen,Xiang-Ying Sun

doi:10.3389/fchem.2021.713104

Ping Li, Jiang-Shan Shen + Show 1 more

Open Access

https://doi.org/10.3389/fchem.2021.713104

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Abstract

In this work, a facile one-pot hydrothermal route was employed to synthesize a series of fluorescent carbon dots (CDs) by using 20 natural amino acids, respectively, as the starting materials. It was found that the CDs synthesized using phenylalanine could possess the intrinsic peroxidase-like activity that could effectively catalyze a traditional peroxidase substrate like 3, 3’, 5, 5’- tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue solution; thereby, a catalytic sensing system for H2O2 has been developed. On the basis of this catalytic reaction, together with the fact that glucose oxidase (GOx) can catalyze the hydrolysis of glucose to generate H2O2, a sensitive catalytic sensing system for glucose could be further established. Furthermore, based on this catalytic reaction, taken together with the two enzymatic catalytic systems of acetylcholinesterase (AChE) and choline oxidase (CHO), a highly sensitive multi-catalytic sensing system could be successfully developed for organophosphorus (OPs) pesticides such as dimethoate, DDVP, and parathion-methyl. Limit of detections (LODs) of H2O2 and glucose were estimated to be 6.5 and 0.84 μM, respectively. The limit of detection of the sub-nM level could be obtained for tested dimethoate, DDVP, and parathion-methyl OPs pesticides. The established sensing systems can exhibit good practical application performance in serum and several fruit samples.

Highlights

Catalysis reaction is an important way to establish extremely sensitive spectral sensing systems
Prins’ group developed a novel way to probe the enzymatic activity by detecting the binding events between oligoanions and the surface of monolayer-coating Au nanoparticles terminated by triazacyclononane·Zn2+ (TACN·Zn2+) complexes. (Bonomi et al, 2011) An activated RNA model substrate, 2-hydroxypropyl-4-nitrophenyl phosphate (HPNP), was employed as the substrate catalyzed by the cooperative interaction of two neighboring TACN·Zn2+ complexes to generate a reporter molecule, the p-nitrophenolate anion
Was 1:2:2:1 in the H2O2/DMPO/carbon dots (CDs)-phenylalanine system. These results indicated that the catalytic activity of CD-phenylalanine varying concentrations of the second substrate for TMB (A) and H2O2 (B)

Summary

Introduction

Catalysis reaction is an important way to establish extremely sensitive spectral sensing systems. (Bonomi et al, 2011) An activated RNA model substrate, 2-hydroxypropyl-4-nitrophenyl phosphate (HPNP), was employed as the substrate catalyzed by the cooperative interaction of two neighboring TACN·Zn2+ complexes to generate a reporter molecule, the p-nitrophenolate anion. Oligoanions such as ATP acted as competitive inhibitors for the binding between HPNP and the TACNZnII head and could turn off the catalytic activity of the system. On the basis of the reported works above, is developing novel catalytic systems with high catalytic activity important and we believe that developing novel catalytic sensing systems by introducing multi-catalytic reactions will substantially improve the sensitivity

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Conclusion