Electrochemical Behaviour of Real-Time Sensor for Determination Mercury in Cosmetic Products Based on PANI/MWCNTs/AuNPs/ITO

Abstract

Mercury is a common ingredient found in skin lightening soaps, creams, and makeup-cleansing products. It may cause skin rashes, skin discolouration, and scarring, as well as a reduction in the skin’s resistance to bacterial and fungal infections. By looking at this scenario, developing a sensor that involved a simple procedure and fasts for real-time detection without affecting mercury sensitivity is urgently needed. For that reason, a fast and sensitive electrochemical method was developed to determine mercury in cosmetic products with the composition of polyaniline/multi-walled carbon nanotubes/gold nanoparticles/indium tin oxide sheet using methylene blue as a redox indicator. The significantly enhanced electrochemical performance was observed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In order to detect mercury qualitatively and quantitatively, deposition potential and deposition time were respectively optimised to be 0.10 V and 70 s. The modified sensor was revealed a wide detection range of mercury from 0.01 to 10.00 ppm with a limit of detection of 0.08 ppm. The modified sensor towards mercury with a correlation coefficient (r2) was of 0.9948. Multiple cycling, reproducibility, and consistency of different modified sensors were investigated to verify the modified sensor’s performance. The developed sensing platform was highly selective toward mercury among the pool of possible interferents, and the stability of the developed sensor was ensured for at least 21 days after 10 repeated uses. The proposed method is a fast and simple procedure technique for analysing the mercury levels in cosmetic products.

Novel Amperometric Mercury-Selective Sensor Based on Organic Chelator Ionophore

“…Most of the voltammetric sensors use anodic stripping voltammetry, which allows detection at lower concentrations owing to the pre-concentration; thus, the detection limit obtained in this work is not as low. Nevertheless, the detection limit achieved here was much lower than that in [ 43 , 44 ], which also used preconcentration. Furthermore, the sensor developed by us has the advantage of a simpler platform than in [ 9 , 27 , 44 ].…”

“…Nevertheless, the detection limit achieved here was much lower than that in [ 43 , 44 ], which also used preconcentration. Furthermore, the sensor developed by us has the advantage of a simpler platform than in [ 9 , 27 , 44 ]. On the other hand, only two sensors used fixed potential techniques for mercury measurement and their architecture does not include carbon nanotubes or ionophores.…”

“…The storage stability was assessed by keeping the modified electrode dry at room temperature and performing a calibration curve once a week; after 4 weeks, a decrease of 10% was observed. This is better than that of MB/AuNP/MWCNT/PANI/ITO in [ 44 ], which lost half of the activity after 3 weeks. Other sensors lost 5.5% of the response after one week with daily use [ 26 ], and “no major change” after one month storage was observed for MWCNT-CQD/GCE [ 45 ].…”

Bioengineered multi-walled carbon nanotube (MWCNT) based biosensors and applications thereof

“…Also, a recent study reported the synthesis of PANI/MWCNT/AuNP composites for electrochemical detection of mercury in cosmetic products using methylene blue as a redox indicator. 200…”