Colorimetric Detection of Salicylic Acid in Aspirin Using MIL-53(Fe) Nanozyme.

Ling Liang,Weiyuan Zuo,Yaojing Huang,Wenren Liu,Fanggui Ye,Shulin Zhao

doi:10.3389/fchem.2020.00671

Abstract

The impurity of salicylic acid (SA) in aspirin is a required inspection item for drug quality control. Since free SA is significantly toxic for humans, the content determination of free SA is absolutely necessary to ensure people's health. In this work, a facile colorimetric method was developed for the detection of SA in aspirin by utilizing the MIL-53(Fe) nanozyme. As MIL-53(Fe) possesses enzyme mimicking catalytic activity, 3,3,5,5-tetramethylbenzidine (TMB) can be easily oxidized to blue-oxidized TMB (oxTMB) with the existence of H2O2. Moreover, an inhibition effect on the catalytic activity of the MIL-53(Fe) nanozyme is induced due to the specific complexation between SA and Fe3+ in the center of MIL-53(Fe), which results in a lighter color in the oxTMB. The color change of oxTMB can be seen easily by the naked eye with the addition of different concentrations of SA. Thus, a simple colorimetric platform was established for effectively monitoring SA. A good linear relationship (R2 = 0.9990) was obtained in the concentration range of 0.4–28 μmol L−1, and the detection limit was 0.26 μmol L−1. In particular, the rationally designed system has been well-applied to the detection of SA impurity in aspirin. Satisfyingly, the detection results are highly in accord with those of HPLC. This novel colorimetric platform broadens the application prospects of nanozymes in the field of pharmaceutical analysis.

Highlights

Salicylic acid (SA), as a major phytohormone, generally plays an important role in regulating diverse physiological processes such as defense responses, thermogenesis, and germination (Wang et al, 2010; Marques et al, 2020)
Afterwards, the mass loss was explored via thermogravimetric analysis (TGA), it was ascertained that the first mass loss (∼39.27%) was due to the dehydration of MIL-53(Fe), and the subsequent mass loss (∼56.56%) corresponded to the collapse of MIL53(Fe) into Fe2O3
salicylic acid (SA) were incubated in an acetate buffer for 4 min, TMB and H2O2 were added and the mixture was incubated at 37◦C for 8 min

Summary

INTRODUCTION

Salicylic acid (SA), as a major phytohormone, generally plays an important role in regulating diverse physiological processes such as defense responses, thermogenesis, and germination (Wang et al, 2010; Marques et al, 2020). Yang’s group developed two rhodamine-based fluorescent probes that could realize bioimaging of SA (Wang et al, 2019a) This colorimetric sensor possesses good selectivity and sensitivity toward SA but detection is observable with the naked-eye. Most studies have focused on the design of nanozymes with different activities for colorimetric sensing of biothiols (Xiong et al, 2015; Song et al, 2020), dopamine (Wang et al, 2019b), glutathione reductase (Zhang et al, 2019), and acid phosphatase (Lin et al, 2020) These sensors generally achieve the goal of detection by using reduced substances to interfere with the oxidation of chromogenic substrates or to reduce oxTMB.

RESULTS AND DISCUSSION

CONCLUSIONS

DATA AVAILABILITY STATEMENT