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Tetrabutylammonium-chloride-glycerol of deep eutectic solvent functionalized MnO2: a novel mimic enzyme for the quantitative and qualitative colorimetric detection of L-cysteine.
- Source :
- Analyst; 1/7/2023, Vol. 148 Issue 1, p182-190, 9p
- Publication Year :
- 2023
-
Abstract
- L -Cysteine is a common amino acid that plays an important role in human livelihood and production. Therefore, a novel method for the simultaneous quantitative and qualitative determination of L -cysteine by a colorimetric detection system is proposed. As a viable oxidase mimic, [N<subscript>4444</subscript>]Cl-G/MnO<subscript>2</subscript>, which consisted of MnO<subscript>2</subscript> nanosheets functionalized by a tetrabutylammonium chloride–glycerol ([N<subscript>4444</subscript>]Cl-G) based deep eutectic solvent (DES) was fabricated. Owing to the oxidation of MnO<subscript>2</subscript> nanosheets, [N<subscript>4444</subscript>]Cl-G/MnO<subscript>2</subscript> could oxidize the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into a blue product (oxTMB) with the characteristic UV–vis spectrum absorbance at 652 nm. The oxidation of TMB by DES/MnO<subscript>2</subscript> was inhibited when L -cysteine was introduced, and the absorbance decreased proportionally with the increase in L -cysteine concentration. Due to this inhibition effect, a colorimetric detection system ([N<subscript>4444</subscript>]Cl-G/MnO<subscript>2</subscript>-TMB) was developed for the quantitative determination of L -cysteine. Under optimal conditions, the assay showed good linearity over the concentration range of 0.125–2.00 μg mL<superscript>−1</superscript> with a low detection limit of 5.96 ng mL<superscript>−1</superscript>. A study of the inhibition mechanism demonstrated that the sulfhydryl group of L -cysteine could decompose [N<subscript>4444</subscript>]Cl-G/MnO<subscript>2</subscript> into Mn<superscript>2+</superscript>, thus limiting the conversion of TMB to oxTMB. In addition, the [N<subscript>4444</subscript>]Cl-G/MnO<subscript>2</subscript>-TMB system was used in test strips for the visual qualitative detection of L -cysteine. The selectivity and test strip results demonstrated the high selectivity, simple operation, and rapid response of the [N<subscript>4444</subscript>]Cl-G/MnO<subscript>2</subscript>-TMB system for the qualitative detection of L -cysteine. Given the satisfying performance of the detection strategy, colorimetric sensing based on the [N<subscript>4444</subscript>]Cl-G/MnO<subscript>2</subscript>-TMB system is considered to have prospective application value in the quantitative and qualitative detection of L -cysteine. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00032654
- Volume :
- 148
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Analyst
- Publication Type :
- Academic Journal
- Accession number :
- 160885950
- Full Text :
- https://doi.org/10.1039/d2an01771g