Highly Sensitive Capsaicin Electrochemical Sensor Based on Bimetallic Metal-Organic Framework Nanocage.

Xiao Fang,Rongshuai Duan

doi:10.3389/fchem.2022.822619

Abstract

The content of capsaicin can be used as exotic markers of kitchen recycled oil. In this study, a bimetallic MOF nanocage (FeIII-HMOF-5) was successfully prepared by a one-step solvothermal method and used for electrode modification to prepare a highly sensitive electrochemical sensor for rapid detection of capsaicin. Capsaicin could be selectively immobilized onto the FeIII-HMOF-5 surface during infiltrating adsorption, thus exhibiting very excellent sensing performance. The detection conditions of the sensor were optimized. Under optimum conditions, the electrochemical sensor can linearly detect capsaicin in the range between 1–60 μM with a detection limit of 0.4 μM. In addition, the proposed electrochemical sensor showed excellent stability and selectivity. The real sample tests indicated the proposed electrochemical sensor was comparable to conventional UV spectrophotometry.

Highlights

Capsaicin-like substances are active ingredients obtained from the fruits of the pepper plant and are characterized by their pungency
FeIII-HMOF-5 was synthesized by a one-step solvothermal method (Cheng et al, 2018), in which zinc nitrate hexahydrate and iron acetylacetonate were used as metal nodes, terephthalic acid was used as organic ligand, polyvinylpyrrolidone was used as stabilizer, and N, N-dimethylformamide-ethanol was used as solvent mixture
Faint peaks (19.7°, 18.6°, 20.2°, 24.7°, 25.2°, 26.1°) of FeIII-HMOF-5 can be seen after the adsorption of capsaicin by FeIII-HMOF-5, suggesting the FeIII-HMOF-5 can adsorbed capsaicin into its cavities

Summary

INTRODUCTION

Capsaicin-like substances are active ingredients obtained from the fruits of the pepper plant and are characterized by their pungency. The electrochemical sensor has a surprisingly low detection limit of 460 nM under ideal conditions, with a wide linear range of capsaicin between 1–10 μM and 10–40 μM. The electrochemical performance of bare SPCE is not sufficient for highly sensitive detection of capsaicin, the surface modification of FeIII-HMOF-5 gives it this potential. The FeIII-HMOF-5modified SPCE becomes a portable electrochemical sensor, which makes it possible to detect capsaicin in the field. FeIII-HMOF-5 was synthesized by a one-step solvothermal method (Cheng et al, 2018), in which zinc nitrate hexahydrate and iron acetylacetonate were used as metal nodes, terephthalic acid was used as organic ligand, polyvinylpyrrolidone was used as stabilizer, and N, N-dimethylformamide-ethanol was used as solvent mixture. The supernatant was filtered through an organic membrane (0.45 μm) and used for electrochemical analysis (Wang et al, 2020)

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT