Colorimetric strategy for ascorbic acid detection based on the oxidase‐like activity of silver nanoparticle single‐walled carbon nanotube composites

Abstract

A colorimetric assay for the determination and quantification of ascorbic acid (AA) is presented using silver nanoparticle (AgNP) single-walled carbon nanotube (AgNP/SWCNT) nanocomposites prepared using a microwave-assisted method. The AgNP/SWCNT nanocomposites possessed oxidase-like properties toward 3,3 0 ,5,5 0tetramethylbenzidine (TMB) and could catalyze the oxidation of TMB to form a blue oxidation product (λ max = 652 nm) in the absence of H 2 O 2. AA can specifically inhibit the oxidation of TMB, resulting in a decline of the absorbance value and blue colour fading. As such, amounts of AA can be assessed easily by the unaided eye and quantitatively using an ultraviolet-visible light spectrophotometer. Under the optimal reaction conditions, this strategy showed a good linearity ranging from 0.4 μM to 5.0 μM for AA detection, and the limit of detection was 130 nM. This assay was also applied for AA measurement in vitamin C tablets and juice samples that yielded satisfactory results.

Colorimetric Detection of Antioxidants in Food Samples Using MnO2/Graphene Quantum Dot Composites with Oxidase-like Activity

“…Distinct nanostructured materials have demonstrated excellent oxidase-like properties, including metal oxide- and carbon-based nanozymes. , In this regard, manganese dioxide (MnO 2 ) appears as a promising oxidase nanozyme due to its low cost, non-toxicity, and environmental friendliness. , However, the catalytic activity of MnO 2 nanostructures is, in general, lower than that of natural enzymes. To overcome this problem, the strategy of combining different nanomaterials to obtain a nanozyme composite with superior properties appears as an interesting approach. , The enhancement in performance is usually attributed to the synergistic effects arising from the combination of different physical and chemical properties …”

“…To overcome this problem, the strategy of combining different nanomaterials to obtain a nanozyme composite with superior properties appears as an interesting approach. 20,21 The enhancement in performance is usually attributed to the synergistic effects arising from the combination of different physical and chemical properties. In this work, we successfully developed a composite using MnO 2 embedded with graphene quantum dots (GQD) by a simple and green hydrothermal synthesis using KMnO 4 as the Mn source and ethanol as a nontoxic reductant, as depicted in Scheme 1a.…”

Co nanoparticles decorated with N-doped carbon nanotubes as high-efficiency catalysts with intrinsic oxidase-like property for colorimetric sensing

“…As is well known, AA occupies great importance in many metabolic processes. 42 An abnormal content of AA is generally related to various diseases, for example, deficiency of AA easily induces scurvy, cardiovascular diseases and gingival bleeding 43 while excessive amounts of AA results in diarrhoea, urinary stones and stomach cramps. 44 Hence, a sensitive method for AA detection is highly desired to predict human diseases.…”

CeO2–Co3O4 nanocomposite with oxidase-like activity for colorimetric detection of ascorbic acid

“…Similarly, Ag NPs-single walled carbon nanotube nanocomposite with oxidase-like activity has been used for the colorimetric detection of AA. 20 Compared with the peroxidase mimic, the oxidation of TMB catalyzed by the oxidase mimic does not use H 2 O 2 , which simplifies the determination process.…”